Title of invention: battery state estimation device
Technical field
[One]
This application is a priority claim application for Korean Patent Application No. 10-2019-0030710 filed on March 18, 2019, and all contents disclosed in the specification and drawings of the application are incorporated herein by reference.
[2]
The present invention relates to an apparatus for estimating a state of a battery, and more particularly, to an apparatus for estimating a state of a battery that determines the presence or absence of acceleration of deterioration and a degree of acceleration of deterioration of a battery cell.
Background
[3]
In recent years, as the demand for portable electronic products such as notebook computers, video cameras, portable telephones, etc. is rapidly increasing, and development of electric vehicles, energy storage batteries, robots, satellites, etc., There is an active research on the Korean market.
[4]
Currently commercialized batteries include nickel cadmium batteries, nickel hydride batteries, nickel zinc batteries, and lithium batteries, among which lithium batteries have little memory effect compared to nickel-based batteries, so charging and discharging are free and self-charging rate is very high. It is in the spotlight for its low and high energy density advantage.
[5]
In recent years, as the application range of secondary batteries is expanded, secondary batteries are widely used not only in small portable devices including smart phones, but also in mid- to large-sized devices such as electric vehicles and power storage devices including hybrid vehicles.
[6]
In the case of such a secondary battery, as the use period increases, the performance deteriorates from the initial stage. In addition, estimating the degree of performance degradation of the secondary battery is said to estimate the state of health (SOH) of the secondary battery, and the SOH of the secondary battery is an important factor in determining the replacement timing of the secondary battery.
[7]
Conventionally, the open circuit voltage (OCV) of the battery is measured, and the current flowing into the battery is accumulated until the battery is fully charged, and the accumulated current amount and the measured OCV value are used to fully charge the battery. An apparatus and method for calculating the capacity have been disclosed (Patent Document 1).
[8]
However, Patent Document 1 only discloses a configuration for determining the degree of deterioration of the battery deterioration afterwards by measuring the loss of the battery's full charge capacity. No more specific information is provided. That is, Patent Document 1 only provides information that can determine the current or past state of the battery, the degree of deterioration of the battery, for example, for determining the state of the battery at a future point, such as the predicted deterioration rate or the predicted life of the battery. There is a problem that no specific information is provided.
[9]
(Patent Document 1) KR 10-2016-0011448 A
Detailed description of the invention
Technical challenge
[10]
The present invention has been devised to solve the above problems, and an object of the present invention is to provide a battery state estimation apparatus capable of providing more detailed information on deterioration of a battery cell.
[11]
Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by examples of the present invention. In addition, it will be easily understood that the objects and advantages of the present invention can be realized by means of the claims and combinations thereof.
Means of solving the task
[12]
An apparatus for estimating a battery state according to an aspect of the present invention includes: a voltage measuring unit that measures a voltage of a battery cell and measures an open circuit voltage of the battery cell whenever the measured voltage reaches a reference charging voltage; And receiving the open circuit voltage measured by the voltage measuring unit, calculating at least one of a voltage fluctuation rate and a resistance fluctuation rate based on a result of processing the received open circuit voltage, and when the voltage fluctuation rate is calculated, the calculated voltage Determine the voltage increase/decrease pattern based on the fluctuation rate and pre-stored voltage fluctuation data, and when the resistance fluctuation rate is calculated, determine the resistance increase/decrease pattern based on the calculated resistance fluctuation rate and previously stored resistance fluctuation data, and determine the voltage increase/decrease pattern and resistance increase/decrease It may include a control unit configured to determine a degree of acceleration of deterioration of the battery cell according to at least one of the patterns.
[13]
When both the voltage increase/decrease pattern and the resistance increase/decrease pattern are determined, the control unit determines a first degree of deterioration acceleration of the battery cell based on the determined voltage increase/decrease pattern, and the first deterioration acceleration level is determined based on the determined resistance increase/decrease pattern. It may be configured to determine a second degree of deterioration acceleration of the battery cell independent of the degree of deterioration acceleration.
[14]
The controller may be configured to calculate the voltage variation rate by comparing the received open circuit voltage with a pre-stored reference voltage.
[15]
The pre-stored reference voltage may be configured to include an open circuit voltage when the voltage of the battery cell reaches the reference charging voltage at a predetermined cycle time.
[16]
The pre-stored voltage fluctuation rate data may be configured to include a past voltage fluctuation rate calculated by the control unit whenever the open circuit voltage is measured by the voltage measuring unit.
[17]
The controller calculates a voltage change rate between the calculated voltage change rate and a plurality of voltage change rates included within a predetermined number of cycles from the current cycle of the battery cell among the previously stored voltage change rate data, and based on the calculated voltage change rate It may be configured to determine the voltage increase or decrease pattern.
[18]
When the voltage increase/decrease pattern is determined as a voltage increase pattern, the controller may be configured to determine a degree of deterioration acceleration of the battery cell as a deceleration deterioration according to the calculated voltage change rate.
[19]
When the voltage increase/decrease pattern is determined as the voltage decrease pattern, the control unit may be configured to determine a degree of acceleration of deterioration of the battery cell as either accelerated deterioration or linear deterioration.
[20]
When the calculated voltage change rate is equal to or greater than a preset reference voltage change rate, the control unit may be configured to determine a degree of acceleration of deterioration of the battery cell as linear deterioration.
[21]
When the calculated voltage change rate is less than a preset reference voltage change rate, the control unit may be configured to determine a degree of acceleration of deterioration of the battery cell as accelerated deterioration.
[22]
The control unit may be configured to determine the voltage increase/decrease pattern when the calculated voltage variation rate exceeds a preset voltage lower limit and is less than a preset voltage upper limit.
[23]
The controller may be configured to calculate an internal resistance based on the received open circuit voltage, and to calculate a resistance variation rate by comparing the calculated internal resistance with a pre-stored reference resistance.
[24]
The pre-stored reference resistance may be configured to include a reference resistance calculated based on an open circuit voltage when the voltage of the battery cell reaches the reference charging voltage at a predetermined cycle time.
[25]
The pre-stored resistance variation rate data may be configured to include a past resistance variation rate calculated by the control unit each time the open circuit voltage is measured by the voltage measurement unit.
[26]
The control unit calculates a resistance change rate between the calculated resistance change rate and a plurality of resistance change rates included within a predetermined number of cycles from the current cycle of the battery cell among the previously stored resistance change rate data, and based on the calculated resistance change rate It may be configured to determine the resistance increase or decrease pattern.
[27]
When the resistance increase/decrease pattern is determined as a resistance increase pattern, the controller may be configured to determine a degree of acceleration of deterioration of the battery cell as either accelerated deterioration or linear deterioration according to the calculated resistance change rate.
[28]
When the resistance increase/decrease pattern is determined as the resistance decrease pattern, the control unit may be configured to determine a degree of deterioration acceleration of the battery cell as deceleration deterioration.
[29]
When the calculated resistance change rate is equal to or greater than a preset reference resistance change rate, the control unit may be configured to determine a degree of acceleration of deterioration of the battery cell as accelerated deterioration.
[30]
When the calculated resistance change rate is less than a preset reference resistance change rate, the control unit may be configured to determine a degree of acceleration of degradation of the battery cell as linear degradation.
[31]
The controller may be configured to determine the resistance increase/decrease pattern only when the calculated resistance variation rate exceeds a preset lower limit of resistance.
[32]
A battery pack according to another aspect of the present invention may include a battery state estimation apparatus according to an embodiment of the present invention.
[33]
An electric vehicle according to another aspect of the present invention may include a battery state estimation apparatus according to an embodiment of the present invention.
Effects of the Invention
[34]
According to an aspect of the present invention, not only the degree of deterioration of the battery cell but also the degree of acceleration of deterioration of the battery cell is estimated, the current deterioration state of the battery cell can be more accurately estimated, as well as the future deterioration state of the battery cell. There is an advantage that the prediction can be made more accurately.
[35]
In addition, according to an aspect of the present invention, since the degree of deterioration acceleration of the battery cell is determined by being subdivided into acceleration deterioration, deceleration degeneration, and linear degeneration, there is an advantage that the degree of deterioration progress of the battery cell can be determined in more detail.
[36]
Further, according to an aspect of the present invention, since the degree of acceleration of deterioration of the battery cell is measured through various indicators, there is an advantage that the degree of progression of battery deterioration can be more accurately determined or predicted.
[37]
In addition, according to an aspect of the present invention, since information on the degree of deterioration acceleration based on the open circuit voltage of the battery cell and the degree of degeneration acceleration based on the internal resistance are provided, there is an advantage in that more detailed state information of the battery cell is provided. have.
[38]
The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.
Brief description of the drawing
[39]
Since the following drawings attached to the present specification serve to further understand the technical idea of ​​the present invention together with the detailed description of the present invention to be described later, the present invention is limited to the matters described in such drawings and should not be interpreted.
[40]
1 is a schematic diagram of a battery pack including an apparatus for estimating a battery state according to an exemplary embodiment of the present invention.
[41]
2 is a block diagram schematically illustrating an apparatus for estimating a battery state according to an embodiment of the present invention.
[42]
3 is a diagram illustrating a voltage variation rate of a first battery cell calculated by an apparatus for estimating a battery state according to an exemplary embodiment of the present invention.
[43]
4 is a diagram illustrating a voltage variation rate of a second battery cell calculated by an apparatus for estimating a battery state according to an exemplary embodiment of the present invention.
[44]
FIG. 5 is a diagram illustrating an enlarged view of a section of a voltage variation rate of a first battery cell calculated by an apparatus for estimating a battery state according to an embodiment of the present invention.
[45]
6 is a diagram illustrating an enlarged view of another section of a voltage variation rate of a first battery cell calculated by an apparatus for estimating a battery state according to an exemplary embodiment of the present invention.
[46]
FIG. 7 is an enlarged view illustrating another section of voltage fluctuation rates of a first battery cell calculated by an apparatus for estimating a battery state according to an exemplary embodiment of the present invention.
[47]
FIG. 8 is a diagram illustrating an enlarged view of one section of voltage fluctuation rates of a second battery cell calculated by the battery state estimation apparatus according to an embodiment of the present invention.
[48]
9 is a diagram illustrating a resistance variation rate of a first battery cell calculated by an apparatus for estimating a battery state according to an exemplary embodiment of the present invention.
[49]
10 is a diagram illustrating a change rate of resistance of a second battery cell calculated by an apparatus for estimating a battery state according to an exemplary embodiment of the present invention.
[50]
FIG. 11 is a diagram illustrating an enlarged view of a section of a variation rate of resistance of a first battery cell calculated by an apparatus for estimating a state of a battery according to an embodiment of the present invention.
[51]
12 is a schematic diagram of a process of determining a degree of acceleration of deterioration of a battery cell based on a voltage change rate in the battery state estimation apparatus according to an embodiment of the present invention in a tree form.
[52]
13 is a schematic diagram schematically illustrating a process of determining a degree of acceleration of deterioration of a battery cell based on a resistance change rate in the battery state estimation apparatus according to an embodiment of the present invention in a tree form.
Mode for carrying out the invention
[53]
The terms or words used in the specification and claims should not be construed as limited to their usual or dictionary meanings, and the inventor may appropriately define the concept of terms in order to describe his own invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of ​​the present invention based on the principle that there is.
[54]
Accordingly, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention, and do not represent all the technical spirit of the present invention. It should be understood that there may be equivalents and variations.
[55]
In addition, in describing the present invention, when it is determined that a detailed description of a related known configuration or function may obscure the subject matter of the present invention, a detailed description thereof will be omitted.
[56]
Terms including an ordinal number, such as first and second, are used for the purpose of distinguishing one of various elements from the others, and are not used to limit the elements by such terms.
[57]
Throughout the specification, when a certain part "includes" a certain component, it means that other components may be further included, rather than excluding other components unless specifically stated to the contrary. In addition, terms such as a control unit described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software, or a combination of hardware and software.
[58]
In addition, throughout the specification, when a part is said to be "connected" with another part, it is not only "directly connected", but also "indirectly connected" with another element in the middle Includes.
[59]
[60]
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[61]
1 is a schematic diagram of a battery pack including an apparatus for estimating a battery state according to an exemplary embodiment of the present invention.
[62]
Referring to FIG. 1, a battery state estimation apparatus 100 according to an embodiment of the present invention is electrically connected to a battery module 10 including a plurality of battery cells 11 to each of a plurality of battery cells 11. The state of can be estimated. In addition, the battery state estimation apparatus 100 may be included in the battery pack 1000 together with the battery module 10. 1 illustrates an example in which one battery module 10 and one battery state estimation apparatus 100 are included in the battery pack 1000, but the battery module 10 and the battery state included in the battery pack 1000 The number of estimating devices 100 is not limited to the number shown in FIG. 1. Similarly, the number of battery cells 11 included in the battery module 10 is not limited to the number shown in FIG. 1.
[63]
A detailed configuration of the battery state estimation apparatus 100 will be described with reference to FIG. 2. 2 is a block diagram schematically illustrating an apparatus for estimating a battery state according to an embodiment of the present invention.
[64]
Referring to FIG. 2, the battery state estimation apparatus 100 may include a voltage measurement unit 101 and a control unit 103.
[65]
The voltage measuring unit 101 may measure the voltage of the battery cell 11 included in the battery module 10. That is, the voltage measuring unit 101 may be configured to measure the voltage of each of the battery cells 11 included in the battery module 10. Preferably, the voltage measuring unit 101 may be configured to measure the charging voltage of the battery cell 11.
[66]
For example, in the embodiment illustrated in FIG. 1, the battery state estimation apparatus 100 includes a first battery cell C1, a second battery cell C2, and a third battery cell C3 included in the battery module 10. And voltages when the fourth battery cell C4 is charged may be measured. Specifically, the voltage measurement unit 101 measures the voltage of the first battery cell C1 through the first sensing line SL1 and the second sensing line SL2, and The voltage of the second battery cell C2 may be measured through the sensing line SL3. In addition, the voltage measurement unit 101 measures the voltage of the third battery cell C3 through the third sensing line SL3 and the fourth sensing line SL4, and performs a fourth sensing line SL4 and a fifth sensing line. The voltage of the fourth battery cell C4 may be measured through the line SL5.
[67]
The voltage measurement unit 101 may measure an open circuit voltage (OCV) of the battery cell 11. That is, the voltage measuring unit 101 may measure both the voltage of the battery cell 11 and the open circuit voltage. In particular, the voltage measuring unit 101 may measure the open circuit voltage of each battery cell 11 whenever the measured voltage reaches the reference charging voltage. Here, the reference charging voltage may be a voltage previously set and stored by a user or the like so that the voltage measuring unit 101 can measure the open circuit voltage. That is, the reference charging voltage is a reference value for measuring the open circuit voltage of the battery cell 11 by the voltage measuring unit 101, and when the voltage measuring unit 101 should measure the open circuit voltage of the battery cell 11 If you can provide that timing For example, the predetermined voltage may be set to 4.2V. The voltage measurement unit 101 measures voltages of the plurality of battery cells 11, and calculates the open circuit voltage of the corresponding battery cells 11 whenever the measured voltage of each battery cell 11 reaches a predetermined voltage. Can be measured.
[68]
For example, in the embodiment shown in Fig. 1, it is assumed that for each of the battery cells 11, the reference charging voltage is set to V1 [V]. In this case, the voltage measurement unit 101 may measure the open circuit voltage of the first battery cell C1 when the voltage of the first battery cell C1 reaches V1[V] by charging. Similarly, when the voltage of the second battery cell C2, the third battery cell C3, or the fourth battery cell C4 reaches V1[V], the voltage measuring unit 101 reaches V1[V]. The open circuit voltage of the battery cell 11 can be measured.
[69]
[70]
The control unit 103 may receive the open circuit voltage measured by the voltage measurement unit 101. The control unit 103 is configured to exchange electrical signals with the voltage measurement unit 101 inside the battery state estimation apparatus 100, and may receive the measured open circuit voltage from the voltage measurement unit 101.
[71]
The controller 103 may calculate a voltage fluctuation rate and/or an electric resistance fluctuation rate based on a result of processing the received open circuit voltage. That is, the controller 103 may calculate a voltage fluctuation rate or a resistance fluctuation rate based on the received open circuit voltage, and may calculate both the voltage fluctuation rate and the resistance fluctuation rate.
[72]
For example, in the embodiment shown in FIG. 1, the control unit 103 receives the open circuit voltage of the first battery cell C1 from the voltage measurement unit 101, and receives the open circuit of the first battery cell C1. At least one or more of a voltage variation rate and a resistance variation rate of the first battery cell C1 may be calculated based on the voltage. Similarly, the control unit 103 receives the open circuit voltage of each of the second battery cell C2, the third battery cell C3, and the fourth battery cell C4 from the voltage measurement unit 101, and receives the received open circuit voltage. At least one or more of a voltage variation rate and a resistance variation rate of each of the second battery cell C2, the third battery cell C3, and the fourth battery cell C4 may be calculated according to the voltage.
[73]
When the voltage variation rate is calculated, the controller 103 may determine a voltage increase/decrease pattern based on the calculated voltage variation rate and pre-stored voltage variation rate data. Here, the voltage fluctuation rate data is reference data for comparison with the calculated voltage fluctuation rate, and may be stored in advance. The controller 103 may update the previously stored voltage fluctuation data by adding the calculated voltage fluctuation rate to the previously stored voltage fluctuation data. In addition, the controller 103 may determine a voltage increase/decrease pattern based on the updated voltage change rate data.
[74]
For example, the previously stored voltage fluctuation rate data may be data in which a voltage fluctuation rate calculated in the past by the controller 103 is stored. In this case, the control unit 103 may determine a voltage increase/decrease pattern of the battery cell 11 based on all voltage fluctuation rates calculated from a cycle point in which the reference voltage is calculated.
[75]
The voltage increase/decrease pattern may include various patterns such as a voltage increase pattern, a voltage decrease pattern, or a voltage constant pattern. Hereinafter, for convenience of explanation, it will be described that the voltage increase/decrease pattern includes a voltage increase pattern and a voltage decrease pattern, and the voltage increase pattern includes a voltage constant pattern excluding the voltage decrease pattern.
[76]
In addition, when the resistance variation rate is calculated, the controller 103 may determine a resistance increase/decrease pattern based on the calculated resistance variation rate and previously stored resistance variation rate data. Here, the previously stored resistance variation rate data is reference data for comparison with the calculated resistance variation rate, and may be previously stored in the storage unit 105. The control unit 103 may update the previously stored resistance fluctuation data by adding the calculated resistance fluctuation rate to the previously stored resistance fluctuation data. In addition, the controller 103 may determine a resistance increase/decrease pattern based on the updated resistance change rate data.
[77]
For example, the previously stored resistance variation rate data may be data in which the resistance variation rate calculated in the past by the control unit 103 is stored. In this case, the control unit 103 may determine a resistance increase/decrease pattern of the battery cell 11 based on all resistance change rates calculated after a predetermined cycle time point in which the reference resistance is calculated.
[78]
The resistance increase/decrease pattern may include various patterns such as a resistance increase pattern, a resistance decrease pattern, or a resistance constant pattern. Hereinafter, for convenience of description, it will be described that the resistance increase/decrease pattern includes a resistance increase pattern and a resistance decrease pattern, and the resistance increase pattern includes a resistance constant pattern excluding the resistance decrease pattern.
[79]
The controller 103 may be configured to determine a degree of acceleration of deterioration of the battery cell 11 according to at least one of the determined voltage increase/decrease pattern and the resistance increase/decrease pattern. That is, when the voltage increase/decrease pattern is determined, the controller 103 may determine the degree of deterioration acceleration of the battery cell 11 according to the voltage increase/decrease pattern. In addition, when the resistance increase/decrease pattern is determined, the controller 103 may determine a degree of acceleration of deterioration of the battery cell 11 according to the resistance increase/decrease pattern. Here, the degree of acceleration of deterioration may be information indicating whether the deterioration of the battery cell 11 is getting faster or getting slower.
[80]
For example, the controller 103 may determine a voltage increase/decrease pattern of the first battery cell C1 and determine a degree of acceleration of deterioration of the first battery cell C1 according to the determined voltage increase/decrease pattern. In addition, the control unit 103 may determine a resistance increase/decrease pattern of the first battery cell C1, and may determine a degree of acceleration of deterioration of the first battery cell C1 according to the determined resistance increase/decrease pattern.
[81]
The battery state estimation apparatus 100 according to an embodiment of the present invention does not determine only the degree of deterioration based on the current state of the battery cell 11, but synthesizes the past history and the current battery cell 11 is deteriorating. You can judge the speed. Accordingly, the battery state estimation apparatus 100 according to an embodiment of the present invention provides information that can estimate the state of the battery cell 11 at a future point in time, thereby predicting the life of the battery cell 11 or determining the future state. It has the advantage of being able to provide helpful information.
[82]
In addition, the battery state estimation apparatus 100 according to an embodiment of the present invention, in the charging state of the battery cell 11, the degree of acceleration of deterioration according to the voltage increase or decrease pattern of the battery cell 11 and the resistance of the battery cell 11 By providing all the degree of acceleration of deterioration according to the increase/decrease pattern, there is an advantage of providing more detailed state information for the battery cell 11.
[83]
[84]
In particular, the control unit 103 may independently determine the degree of deterioration acceleration for each of the battery cells 11. For example, the control unit 103 may have a voltage increase/decrease pattern and a resistance increase/decrease pattern for the first battery cell C1, the second battery cell C2, the third battery cell C3, and the fourth battery cell C4, respectively. At least one or more of them may be determined. In addition, the control unit 103 degenerates separately for each of the first battery cell C1, the second battery cell C2, the third battery cell C3, and the fourth battery cell C4 according to the determined voltage increase/decrease pattern. You can judge the degree of acceleration. In addition, the control unit 103 accelerates deterioration separately for each of the first battery cell (C1), the second battery cell (C2), the third battery cell (C3), and the fourth battery cell (C4) according to the determined resistance increase/decrease pattern. You can also judge the degree.
[85]
That is, since the battery state estimation apparatus 100 according to an embodiment of the present invention can independently determine the degree of deterioration acceleration of each of the battery cells 11, the degree of deterioration and the degree of deterioration acceleration of each of the battery cells 11 There is an advantage of determining and further predicting the lifetime of each of the battery cells 11. Specifically, the battery state estimation apparatus 100 can calculate the loss capacity by measuring the open circuit voltage of each of the battery cells 11 to calculate the degree of deterioration of each of the battery cells 11. ) It is possible to determine the degree of acceleration of degeneration in terms of how quickly each degeneration is occurring. Accordingly, the battery state estimation apparatus 100 may estimate the degree of deterioration of each of the battery cells 11 in the future according to the degree of acceleration of deterioration of the battery cells 11, and the degree of deterioration of each of the battery cells 11 It has the advantage of being able to adjust the control conditions.
[86]
For example, even the battery cells 11 of the same product line may not have exactly the same usable capacity due to problems such as initial resistance variation or capacity variation. For example, it is assumed that the set capacity of the battery cell is 1000 mAh at the time of shipment, but the initial capacity of the first battery cell C1 is 900 mAh, and the initial capacity of the second battery cell C2 is 1000 mAh. When the current usable capacity of the first battery cell C1 and the second battery cell C2 becomes the same as 800 mAh due to use for the same period, the first battery cell C1 and the second battery cell C2 are the same. Although they have usable capacity, determining that the degree of deterioration of the two battery cells 11 is the same due to the difference in initial capacity cannot be regarded as an accurate state estimation of the battery cells 11. In addition, even if the degree of degeneration of the first battery cell C1 is approximately 11% and the degree of deterioration of the second battery cell C2 is calculated as 20%, the calculated degree of degeneration is the first according to the current capacity compared to the initial capacity. It is an indicator that indicates only the current state of each of the battery cells C1 and C2, and is only meaningful, and the degree of acceleration of deterioration or acceleration of deterioration of the current first and second battery cells C1 and C2 It is not suitable as a predictive index for the future situation such as the expected life span according to. That is, the ratio of the current capacity to the initial capacity of the battery cell 11 is only an index to determine the degree of deterioration of the battery cell 11 ex post, and the degree of acceleration of the deterioration of the battery cell 11, the rate of deterioration in the future, or an estimate There is a problem that it is not appropriate to be used as an index to judge lifespan, etc.
[87]
On the other hand, the battery state estimation apparatus 100 according to an embodiment of the present invention may accurately determine the current state of the battery cell 11 by determining the degree of acceleration of deterioration of the current battery cell 11. In addition, the battery state estimation apparatus 100 determines the degree of acceleration of deterioration of the battery cell 11 and takes measures such as changing the control condition of the battery cell 11 so that the life of the battery cell 11 lasts longer. There are advantages to take.
[88]
[89]
Here, the controller 103 includes a processor known in the art, an application-specific integrated circuit (ASIC), another chipset, in order to execute various control logics performed in the battery state estimation apparatus 100 according to an embodiment of the present invention. Logic circuits, registers, communication modems, data processing devices, and the like may be optionally included. In addition, when the control logic is implemented in software, the control unit 103 may be implemented as a set of program modules. In this case, the program module may be stored in a memory and executed by a processor. The memory may be inside or outside the processor, and may be connected to the processor by various well-known means. For example, the control unit 103 is a processor provided in the battery state estimation apparatus 100 according to an embodiment of the present invention, and determines the degree of deterioration acceleration of the battery cell 11 by using an output device such as a display device. It can be provided to the user through. In addition, the controller 103 may provide a replacement or warning notification of the battery cell 11 to the user through an external notification device based on the degree of acceleration of the deterioration of the battery cell 11.
[90]
[91]
In addition, referring to FIG. 2, the apparatus 100 for estimating a battery state according to an embodiment of the present invention may further include a storage unit 105. The storage unit 105 may store the voltage fluctuation rate data and the resistance fluctuation rate data. That is, the storage unit 105 may store voltage fluctuation rate data and resistance fluctuation rate data calculated from the control unit 103 in the past. The control unit 103 may determine a voltage increase/decrease pattern of the battery cell 11 based on the voltage change rate data previously stored in the storage unit 105. In addition, the control unit 103 may determine a resistance increase/decrease pattern of the battery cell 11 based on the resistance change rate data previously stored in the storage unit 105.
[92]
That is, the storage unit 105 performs operations and functions of each component of the battery state estimation apparatus 100 according to an embodiment of the present invention, such as past voltage fluctuation data and resistance fluctuation data calculated by the control unit 103. You can save the data or programs you need. If the storage unit 105 is a known information storage means known to be capable of recording, erasing, updating and reading data, there is no particular limitation on its type. As an example, the information storage means may include RAM, flash memory, ROM, EEPROM, register, and the like. The storage unit 105 may store program codes in which processes executable by the control unit 103 are defined.
[93]
[94]
When both the voltage increase/decrease pattern and the resistance increase/decrease pattern are determined, the controller 103 may determine a first degree of acceleration of deterioration of the battery cell 11 based on the determined voltage increase/decrease pattern. For example, in the embodiment shown in FIG. 1, the controller 103 determines a voltage increase/decrease pattern of the first battery cell C1, and a first deterioration acceleration of the first battery cell C1 based on the determined voltage increase/decrease pattern. You can judge the degree. Also, the controller 103 may be configured to determine a second degree of deterioration acceleration of the battery cell 11 independent of the first degree of degeneration acceleration based on the determined resistance increase/decrease pattern. In the previous example, the control unit 103 determines a resistance increase/decrease pattern of the first battery cell C1 independently of the first deterioration acceleration degree of the first battery cell C1, and the first battery cell C1 The second degree of acceleration of deterioration of the battery cell C1 may be determined. That is, when determining both the voltage increase/decrease pattern and the resistance increase/decrease pattern of the first battery cell C1, the control unit 103 determines a first degree of degeneration acceleration and a second degree of degeneration acceleration independently of each other. Can be calculated.
[95]
Specifically, in the discharge situation of the battery cell 11, the open circuit voltage may have an influence on the change factor of the resistance. For example, when the battery cell 11 is discharged, since the increase or decrease of the open circuit affects the increase or decrease of the resistance, the increase or decrease of the open circuit voltage and the increase or decrease of the resistance may appear oppositely. That is, in the discharge situation, the degree of acceleration of deterioration of the battery cell 11 should be determined in consideration of the specificity of the open circuit voltage affecting the resistance change factor of the battery cell 11. However, in the charging situation, since the increase or decrease of the open circuit voltage and the increase or decrease of the resistance of the battery cell 11 are independent factors that do not affect each other, the control unit 103 determines the first degree of deterioration acceleration based on the voltage increase/decrease pattern. Alternatively, the second degree of deterioration acceleration may be determined based on the resistance increase/decrease pattern independently from the first degree of deterioration acceleration.
[96]
Battery state estimation apparatus 100 according to an embodiment of the present invention, in consideration of the specificity of the charging situation in which the open circuit voltage and resistance do not affect each other, based on the degree of deterioration acceleration based on the voltage increase or decrease pattern and the resistance increase or decrease pattern. The degree of acceleration of degeneration can all be judged. Accordingly, the battery state estimation apparatus 100 according to an embodiment of the present invention has an advantage of helping to determine the state of the battery cell 11 by providing various information on the state of the battery cell 11. .
[97]
[98]
In the above, it has been described that the control unit 103 can determine the degree of deterioration acceleration of the battery cell 11 based on each of the voltage increase/decrease pattern and the resistance increase/decrease pattern in the charging situation of the battery cell 11. Hereinafter, determination of a first degree of deterioration acceleration based on a voltage increase/decrease pattern and determination of a second degree of degeneration acceleration based on a resistance increase/decrease pattern will be described in detail.
[99]
First, the determination of the degree of acceleration of the first deterioration based on the voltage increase/decrease pattern will be described. The controller 103 may calculate a voltage variation rate by comparing the received open circuit voltage with a pre-stored reference voltage. Here, the pre-stored reference voltage is a reference value for comparison with the open circuit voltage measured by the voltage measurement unit 101 and may be a value previously stored in the storage unit 105. That is, the reference voltage is pre-stored in the storage unit 105, and the control unit 103 compares the reference voltage previously stored in the storage unit 105 with the open circuit voltage received from the voltage measurement unit 101 to obtain a voltage fluctuation rate. Can be calculated.
[100]
For example, the pre-stored reference voltage may include the open circuit voltage of the battery cell 11 measured at a predetermined cycle time. The voltage fluctuation rate may be obtained by comparing a pre-stored reference voltage with an open circuit voltage received from the voltage measurement unit 101 by the control unit 103. In particular, the voltage variation rate may be calculated as a ratio or difference between a previously stored reference voltage and a measured value of the open circuit voltage. That is, the control unit 103 receives the open circuit voltage measured from the voltage measurement unit 101 in a cycle after the predetermined cycle time point, and calculates the ratio of the received open circuit voltage to a pre-stored reference voltage as a voltage change rate. can do.
[101]
For example, it is assumed that the reference voltage previously stored for the first battery cell C1 is A1[V]. In addition, it is assumed that the open circuit voltage of the first battery cell C1 measured by the voltage measuring unit 101 at the first point in time is B1[V]. The controller 103 may calculate a voltage change rate of the first battery cell C1 at a first time point as a difference between A1 and B1. For example, the voltage fluctuation rate of the first battery cell C1 at the first point in time may be calculated by a calculation formula of B1-A1. As another example, the voltage change rate at the first point in time of the first battery cell C1 may be calculated by a calculation formula of “(B1 ÷ A1)×100”. Hereinafter, for convenience of explanation, the voltage fluctuation rate is limited to the one calculated by the calculation formula of B1-A1.
[102]
Preferably, the pre-stored reference voltage may include an open circuit voltage when the battery cell 11 is charged at a predetermined cycle time and the voltage of the battery cell 11 reaches the reference charging voltage. Here, the predetermined cycle time is a time within a predetermined number of cycles from the beginning of life (BOL), and may be, for example, the first charging time after shipment of the battery cell 11.
[103]
For example, it is assumed that the reference charging voltage is set to 4.2V. In this case, the voltage measurement unit 101 may measure the voltage in the initial charging process (initial state) of the first battery cell C1 and measure the open circuit voltage when the measured voltage reaches 4.2V. have.
[104]
Preferably, the pre-stored voltage fluctuation data may be configured to include a voltage fluctuation rate calculated by the control unit 103 whenever the open circuit voltage is measured by the voltage measurement unit 101. That is, from the predetermined cycle time to the current time point, the voltage measurement unit 101 measures the open circuit voltage when the voltage of the battery cell 11 reaches the reference charging voltage by charging, and the control unit 103 May calculate a voltage variation rate according to the open circuit voltage measured by the voltage measuring unit 101. In addition, the calculated voltage fluctuation rate may be included in the voltage fluctuation rate data previously stored in the storage unit 105.
[105]
For example, in the embodiment shown in FIG. 1, the voltage fluctuation rate data previously stored for the first battery cell C1 includes the voltage fluctuation rate of the first battery cell C1 calculated at the first time point to the N-1th time point. I can. Here, N is an integer greater than or equal to 2, and when N is 2, only the voltage variation rate of the first battery cell C1 calculated at the first time point may be included in the previously stored voltage variation rate data. When the voltage change rate of the first battery cell C1 is calculated by the control unit 103 at the Nth time point, the voltage change rate of the first battery cell C1 calculated at the Nth time point is previously stored in the storage unit 105. It can be included in the voltage change rate data. In this case, the voltage fluctuation rate data previously stored in the storage unit 105 may include first to Nth voltage fluctuation rates.
[106]
The battery state estimation apparatus 100 according to an embodiment of the present invention may determine a voltage increase/decrease pattern of the current battery cell 11 based on voltage change rate data previously stored in the storage unit 105 from a past point of time to a current point of time. . That is, the battery state estimation apparatus 100 according to an embodiment of the present invention determines the voltage increase/decrease pattern and the degree of deterioration acceleration of the current battery cell 11 based on pre-stored voltage fluctuation data that accumulates and stores the calculated voltage fluctuation rate. Therefore, there is an advantage in that it is possible to more accurately determine the degree of deterioration acceleration and degree of deterioration of the battery cell 11 than the case of determining the degree of deterioration of the battery cell 11 only with the voltage change rate at a specific point in time. In addition, since the deterioration acceleration degree and deterioration degree determined in this way can be used as information for estimating the future state of the battery cell 11, the battery state estimation apparatus 100 according to an embodiment of the present invention is a battery cell. There is an advantage of providing information that can estimate the future state based on the degree of acceleration of deterioration as well as the past and present state of (11).
[107]
[108]
The controller 103 may calculate a rate of change of a plurality of voltage fluctuation rates included within a predetermined number of cycles from the current cycle of the battery cell 11 from among the previously stored voltage fluctuation data. Here, the voltage change rate may include an average rate of change or an instantaneous rate of change between voltage fluctuation rates. Further, the plurality of voltage fluctuation rates included within a predetermined number of cycles from the current cycle may include a plurality of voltage fluctuation rates included within a preset number of cycles from the current cycle. For example, the controller 103 may calculate a voltage change rate of a plurality of voltage change rates included within 50 cycles from the current cycle. The calculation of the voltage change rate will be described in detail with reference to FIGS. 3 and 4.
[109]
3 is a diagram illustrating a voltage variation rate of a first battery cell calculated by an apparatus for estimating a battery state according to an exemplary embodiment of the present invention. 4 is a diagram illustrating a voltage variation rate of a second battery cell calculated by an apparatus for estimating a battery state according to an exemplary embodiment of the present invention. 3 and 4, the storage unit 105 stores voltage fluctuation rate data previously stored for the first battery cell C1 and voltage fluctuation rate data previously stored for the second battery cell C2 every cycle. I can. Hereinafter, as shown in FIG. 3, a section including a preset number of cycles for the first battery cell C1 will be described as an In section. Similarly, as shown in FIG. 4, a section including a preset number of cycles for the second battery cell C2 will be described as a Jn section. Here, n is a positive integer. For example, when the preset number of cycles is 50, the I1 section may include 0 to 50 cycles of the first battery cell C1, and the I2 section may include 51 to 100 cycles of the first battery cell C1. For convenience of explanation, it will be described that the 0 cycle of the first battery cell C1 is included in I1, and the 0 cycle of the second battery cell C2 is included in the J1 period.
[110]
For example, it is assumed that the number of cycles preset to be included in one section is 50. In FIG. 3, if the current cycle of the first battery cell C1 is 300 cycles, the control unit 103 stores 251 to 300 cycles of the voltage change rate data previously stored for the first battery cell C1 in the storage unit 105. The voltage fluctuation rate of each cycle belonging to the included section I6 can be extracted. That is, the control unit 103 may calculate the voltage change rate of the period I6 by comparing the voltage change rate of each cycle belonging to the period I6 of the first battery cell C1 with each other. Similarly, in FIG. 4, if the current cycle of the second battery cell C2 is 150 cycles, the control unit 103 includes 101 to 150 of the voltage change rate data previously stored for the second battery cell C2 in the storage unit 105. It is possible to extract the voltage change rate of each cycle in the J3 section including the cycle. The controller 103 may calculate a voltage change rate of the period J3 by comparing the voltage change rates of each cycle in the period J3 of the second battery cell C2 with each other. Here, the voltage change rate means a specific value for the rate of change.
[111]
[112]
Hereinafter, for convenience of explanation, if the voltage change rate is greater than or equal to 0, it will be described as a positive rate of change, and if the voltage change rate is less than 0, it will be described as a negative rate of change. In addition, an example in which the control unit 103 calculates a voltage change rate will be described in detail with reference to FIG. 5.
[113]
FIG. 5 is a diagram illustrating an enlarged view of a section of a voltage variation rate of a first battery cell calculated by an apparatus for estimating a battery state according to an embodiment of the present invention. That is, FIG. 5 is a diagram showing an enlarged view of the voltage variation rate included in the section I2 among the voltage variation rates calculated for the first battery cell C1.
[114]
Referring to the embodiment of FIG. 5, the controller 103 may calculate a voltage change rate of a voltage change rate included in a section in which the cycle of the current battery cell 11 belongs. In this case, the controller 103 may classify a section to which the current cycle of the battery cell 11 belongs into a plurality of sub-sections based on a voltage change rate of a section in which the current cycle of the battery cell 11 belongs. Specifically, the control unit 103 converts one section into a plurality of sub-sections based on a cycle point at which the voltage change rate calculated within a section changes from a positive rate of change to a negative rate of change, or from a negative rate of change to a positive rate of change. Can be distinguished. For example, in the example of FIG. 5, the control unit 103 may calculate an average rate of change for continuous cycles included in section I2 or an instantaneous rate of change for continuous cycles included in section I2. Specifically, based on 80 cycles, the voltage change rate of the I21 section may be calculated as a positive rate of change, and the I22 voltage change rate may be calculated as a negative rate of change. Accordingly, the controller 103 may divide the I2 section of the first battery cell C1 into an I21 section and an I22 section based on 80 cycles.
[115]
That is, in the embodiment of FIG. 5, the control unit 103 may calculate the voltage change rate for each of the I21 and I22 sections by dividing the I2 section into I21 and I22 sections. In this way, the controller 103 may divide one section into sub sections and calculate a voltage change rate for each sub section.
[116]
6 is a diagram illustrating an enlarged view of another section of a voltage variation rate of a first battery cell calculated by an apparatus for estimating a battery state according to an exemplary embodiment of the present invention. FIG. 7 is an enlarged view illustrating another section of voltage fluctuation rates of a first battery cell calculated by an apparatus for estimating a battery state according to an exemplary embodiment of the present invention.
[117]
6 and 7, the control unit 103 may divide the I4 section and the I6 section into a plurality of sub-sections according to the calculated voltage change rate. That is, the control unit 103 may divide the I4 section into I41, I42, I43, and I44 sub-sections, and divide the I6 section into I61 and I62 sub-sections.
[118]
FIG. 8 is a diagram illustrating an enlarged view of one section of voltage fluctuation rates of a second battery cell calculated by the battery state estimation apparatus according to an embodiment of the present invention.
[119]
Referring to FIG. 8, the controller 103 may divide the J1 section into a plurality of sub-sections according to the voltage change rate calculated for the second battery cell C2. That is, the controller 103 may divide the J1 section into J11 and J12 sub-sections.
[120]
When calculating the rate of change between the voltage fluctuation rates included in the section to which the current cycle of the battery cell 11 belongs, the controller 103 may not calculate the rate of change by determining only one section to which the current cycle belongs. In addition, the control unit 103 determines a cycle time at which the voltage change rate changes from a positive rate of change to a negative rate of change, or from a negative rate of change to a positive rate of change, and the current cycle of the battery cell 11 is based on the determined cycle time. The section to which it belongs can be divided into sub sections.
[121]
In this way, the battery state estimation apparatus 100 according to an embodiment of the present invention does not uniformly determine that the section to which the current cycle of the battery cell 11 belongs is only one section, but divides the sub section into voltage Since the rate of change is calculated in more detail, there is an advantage in that the current state of the battery cell 11 can be more accurately determined.
[122]
Also, the controller 103 may determine a voltage increase/decrease pattern based on the calculated voltage change rate. Here, the voltage increase/decrease pattern may include a voltage increase pattern and a voltage decrease pattern. In particular, the control unit 103 may determine a voltage increase or decrease pattern when the calculated change rate is a positive change rate as the voltage increase pattern. In addition, the controller 103 may determine a voltage increase/decrease pattern when the calculated rate of change is a negative rate of change as the voltage decrease pattern.
[123]
For example, referring to FIGS. 3 and 5, when the current cycle of the first battery cell C1 belongs to the period I1, the control unit 103 determines the first battery cell C1 based on the voltage change rate included in the period I1. The voltage change rate of can be calculated. In this case, the control unit 103 may calculate the voltage change rate of the section I1 as a value equal to or greater than 0. That is, the voltage change rate of the I1 section may be calculated as a positive change rate. In addition, the controller 103 may determine the current voltage increase/decrease pattern of the first battery cell C1 as the voltage increase pattern based on the result of calculating the voltage change rate as a positive change rate. In addition, when the current cycle of the first battery cell C1 belongs to the I22 section of the I2 section, the controller 103 may calculate a negative rate of change based on the voltage variation rate included in the section. In addition, the controller 103 may determine a current voltage increase/decrease pattern of the first battery cell C1 as a voltage decrease pattern based on the calculated negative change rate.
[124]
For example, referring to FIGS. 4 and 8, when the current cycle of the second battery cell C2 belongs to the J1 section, the controller 103 may calculate the voltage change rate based on the voltage change rate included in the J1 section. . At this time, when the current cycle of the second battery cell C2 belongs to the J11 section, the controller 103 calculates the voltage change rate of the second battery cell C2 as a value equal to or greater than 0, and the voltage increase/decrease pattern as a voltage increase pattern. You can decide. Conversely, when the current cycle of the second battery cell C2 belongs to the period J12, the controller 103 calculates the voltage change rate of the second battery cell C2 to a value less than 0, and the voltage increase/decrease pattern is a voltage decrease pattern. Can be determined by
[125]
And, when the current cycle of the second battery cell C2 belongs to any one of the intervals J2 to J6, the control unit 103 calculates the voltage change rate of the second battery cell C2 as a negative change rate, and the calculated sound The voltage increase/decrease pattern of the current second battery cell C2 may be determined as the voltage decrease pattern based on the change rate of.
[126]
That is, the battery state estimation apparatus 100 according to an embodiment of the present invention has the advantage of being able to more accurately estimate the current state of the battery cell 11 by considering not only the current state of the battery cell 11 but also the past state. There is this. In addition, since the battery state estimation apparatus 100 according to an embodiment of the present invention calculates a voltage change rate of the battery cell 11 and determines a voltage increase/decrease pattern based on the voltage change rate, the future of the battery cell 11 There is an advantage of being able to provide information that makes it easy to estimate the state. In addition, even within a predetermined number of cycles from the current cycle, by dividing the section in which the voltage change rate varies from negative to positive or from positive to negative into sub-sections to determine the voltage increase/decrease pattern of the battery cell 11 in more detail and detail, There is an advantage of being able to more accurately estimate the current state of the battery cell 11.
[127]
[128]
The controller 103 may determine a first degree of deterioration acceleration of the battery cell 11 as an acceleration deterioration, a linear deterioration, or a deceleration deterioration according to a voltage increase/decrease pattern of the battery cell 11. Here, the accelerated deterioration is a state in which the deterioration of the battery cell 11 is gradually accelerated, and the linear deterioration refers to a state in which the deterioration of the battery cell 11 is not accelerated gradually like the accelerated deterioration, but continues linearly and constant. . On the contrary, deceleration deterioration refers to a state in which deterioration of the battery cells 11 is progressing slowly. Hereinafter, the determination of the first degree of deterioration acceleration according to the voltage increase/decrease pattern will be described.
[129]
When determining the voltage increase/decrease pattern as the voltage increase pattern, the controller 103 may be configured to determine a first degree of deterioration acceleration of the battery cell 11 as deceleration deterioration.
[130]
For example, referring to FIG. 3 as in the previous example, when the current cycle of the first battery cell C1 belongs to the period I1, the control unit 103 converts the voltage increase/decrease pattern of the first battery cell C1 into a voltage increase pattern. You can decide. The controller 103 may determine a current degree of first deterioration acceleration of the first battery cell C1 as deceleration deterioration. That is, when determining the voltage increase/decrease pattern of the battery cell 11 as the voltage increase pattern, the controller 103 may determine the degree of deterioration acceleration of the battery cell 11 as only the deceleration deterioration.
[131]
As in the previous example, referring to FIG. 4, when the current cycle of the second battery cell C2 belongs to the J2 section, the control unit 103 determines the voltage increase/decrease pattern of the second battery cell C2 as the voltage decrease pattern. I can. The controller 103 may determine the degree of acceleration of the first deterioration of the second battery cell C2 as either accelerated deterioration or linear deterioration according to the voltage change rate of the section J2 determined as the voltage decrease pattern.
[132]
That is, when determining the voltage increase/decrease pattern as the voltage decrease pattern, the control unit 103 may determine the first degree of deterioration acceleration as accelerated deterioration or linear deterioration based on the voltage change rate of the battery cell 11. Conversely, when the voltage increase/decrease pattern is determined as the voltage increase pattern, the controller 103 may be configured to omit the process of calculating the voltage change rate of the battery cell 11 and determine the first degree of deterioration acceleration as only deceleration deterioration.
[133]
The battery state estimation apparatus 100 according to an embodiment of the present invention accelerates the first deterioration acceleration degree of the battery cell 11 according to the voltage increase/decrease pattern and the voltage change rate of the battery cell 11 to accelerate deterioration, linear degeneration, or deceleration. By subdividing into deterioration and determining, there is an advantage in that the current state of the battery cell 11 can be more accurately determined and diagnosed.
[134]
In addition, when the voltage increase/decrease pattern is determined as the voltage increase pattern, the battery state estimation apparatus 100 may not separately calculate the voltage change rate. That is, the battery state estimation apparatus 100 determines the degree of deterioration acceleration of the battery cell 11 as deceleration deterioration only when the voltage increase/decrease pattern of the battery cell 11 is determined as the voltage increase pattern, There is an advantage of saving the time required to determine the degree of acceleration.
[135]
[136]
Accelerated deterioration and linear deterioration among the degree of deterioration acceleration of the battery cell 11 can be classified according to how fast the deterioration of the battery cell 11 is proceeding. Hereinafter, a classification criterion for accelerated deterioration and linear degeneration will be described.
[137]
When the calculated voltage change rate is greater than or equal to a preset reference voltage change rate, the controller 103 may be configured to determine a degree of acceleration of deterioration of the battery cell 11 as linear deterioration.
[138]
Conversely, when the calculated voltage change rate is less than a preset reference voltage change rate, the controller 103 may be configured to determine the degree of acceleration of deterioration of the battery cell 11 as accelerated deterioration.
[139]
Here, the preset reference voltage change rate is a reference rate of change for determining the degree of deterioration acceleration as accelerated deterioration or linear degeneration when the voltage increase/decrease pattern of the battery cell 11 is determined as the voltage decrease pattern.
[140]
For example, the preset reference voltage change rate may be preset to decrease the voltage change rate by 1 mV every 50 cycles. 5, 6, and 8, if the current cycle of the first battery cell C1 belongs to any one of the periods I22, I42, I44, or I62, the controller 103 is the first battery cell. The voltage change rate of the section to which the current cycle of (C1) belongs may be compared with a preset reference voltage change rate.
[141]
If the voltage change rate of the section in which the current cycle of the first battery cell C1 belongs is equal to or greater than the preset reference voltage change rate, the controller 103 determines that the voltage change rate is linearly deteriorated, and the voltage of the section to which the current cycle of the first battery cell C1 belongs. If the rate of change is less than the preset rate of change of the reference voltage, it may be determined as accelerated deterioration.
[142]
Similarly, in the embodiment shown in FIGS. 4 and 8, if the current cycle of the second battery cell C2 belongs to any one of the intervals J12, J2, J3, J4, J5 or J6, the controller 103 2 The voltage change rate of the section to which the current cycle of the battery cell C2 belongs may be compared with a preset reference voltage change rate. Preferably, referring to FIGS. 4 and 5, if the current cycle of the second battery cell C2 belongs to any one of the intervals J12, J2 to J6, the controller 103 is The voltage change rate of the section to which the cycle belongs may be compared with a preset reference voltage change rate.
[143]
Here, the controller 103 may divide the J1 section into a J11 section and a J12 section based on the voltage change rate of the J1 section. In the process of calculating the voltage change rate of the J1 section, the controller 103 may divide the J1 section into a J11 section and a J12 section based on a point at which the voltage increase/decrease pattern changes. Here, since the voltage increase/decrease pattern in the J11 section is a voltage increase pattern and the voltage increase/decrease pattern in the J12 section is a voltage decrease pattern, the controller 103 may divide the J1 section into the J11 and J12 sections based on 25 cycles. That is, section J11 and section J12 may be sub-sections of section J1.
[144]
For example, if the current cycle of the second battery cell C2 belongs to the section J11, the control unit 103 determines the second battery cell C2 based on the voltage change rate of the section to which the current cycle of the second battery cell C2 belongs. The voltage increase/decrease pattern of may be determined as the voltage increase pattern. In addition, the control unit 103 may determine the first degree of deterioration acceleration of the second battery cell C2 as deceleration deterioration.
[145]
As another example, it is assumed that the voltage change rates in the intervals J12, J2, and J3 are less than the preset voltage change rates, and the voltage change rates in the intervals J4, J5 and J6 are equal to or greater than the preset voltage change rates. If the current cycle of the second battery cell C2 belongs to any one of periods J12, J2, or J3, the controller 103 may determine a first degree of acceleration of deterioration of the second battery cell C2 as accelerated deterioration. . Conversely, if the current cycle of the second battery cell C2 belongs to any one of the intervals J4, J5, or J6, the control unit 103 determines the degree of acceleration of the first degradation of the second battery cell C2 as linear degradation. I can.
[146]
That is, the battery state estimation apparatus 100 according to an embodiment of the present invention does not uniformly determine the degree of deterioration acceleration for the voltage increase pattern, and the preset reference voltage change rate and the period in which the current cycle of the battery cell 11 belongs. You can compare the rate of change in voltage. In addition, the battery state estimation apparatus 100 may determine the degree of deterioration acceleration of the battery cell 11 by subdividing it into accelerated deterioration or linear degeneration. Accordingly, there is an advantage that the current state of the battery cell 11 can be further subdivided and diagnosed in detail.
[147]
[148]
The controller 103 may be configured to determine a voltage increase/decrease pattern of the battery cell 11 only when the voltage fluctuation rate calculated for the battery cell 11 exceeds a preset voltage lower limit and is less than a preset voltage upper limit. That is, the control unit 103 may determine the voltage increase/decrease pattern only when the voltage change rate of the battery cell 11 is within a certain range.
[149]
For example, when the voltage fluctuation rate of the battery cell 11 is greater than or equal to a preset upper limit value, the open circuit voltage of the battery cell 11 is increased above the reference value, and the battery cell 11 is abnormally deteriorated and there is a risk of a sudden drop. ) May be present. In addition, when the voltage fluctuation rate of the battery cell 11 is less than or equal to a preset lower limit, the open circuit voltage of the battery cell 11 decreases below the reference value due to an electric short or the like, and the battery cell 11 is abnormally deteriorated. Can be
[150]
Accordingly, the control unit 103 may determine a voltage increase/decrease pattern for the case where the battery cell 11 is normally degraded, except for the case where the battery cell 11 is abnormally deteriorated.
[151]
If the classification of the normal state or the abnormal state of the battery cell 11 is not processed in advance, the degree of deterioration acceleration is determined according to the voltage increase/decrease pattern in the abnormal state, and the battery control condition is adjusted according to the determined degree of deterioration acceleration, There is a problem that can further worsen the state of the battery cell 11.
[152]
Therefore, the battery state estimation apparatus 100 according to an embodiment of the present invention first classifies the state of the battery cell 11 into a normal state or an abnormal state, and then only when the state of the battery cell 11 is a normal state. By determining the voltage increase/decrease pattern and the degree of deterioration acceleration, there is an advantage in that the time required for determining the degree of deterioration acceleration of the battery cell 11 can be shortened and the accuracy of determining the state of the battery cell 11 can be improved.
[153]
[154]
In the above, a description has been given of the content in which the control unit 103 determines the first degree of deterioration acceleration of the battery cell 11 based on a voltage increase/decrease pattern in the charging situation of the battery cell 11. Hereinafter, determination of a second degree of acceleration of deterioration based on a resistance increase/decrease pattern will be described in detail.
[155]
Here, the second degree of deterioration acceleration is a degree of degeneration acceleration determined according to the resistance increase/decrease pattern of the battery cell 11, and may be determined as one of acceleration deterioration, linear degeneration, or deceleration deterioration, similar to the first degree of degeneration acceleration described above.
[156]
First, the control unit 103 may calculate the internal resistance of the battery cell 11 based on the open circuit voltage of the battery cell 11 measured by the voltage measurement unit 101.
[157]
For example, the controller 103 may calculate the current resistance of the battery cell 11 according to the calculation formula of "(|CCV EoC -OCV EoC |) ÷ i t1 ". Here, CCV EoC is the charging or discharging voltage of the battery cell 11 measured after the time t1 from the time when OCV EoC of the battery cell 11 is measured, and OCV EoC is the voltage of the battery cell 11 in the charging situation. It is the open circuit voltage of the battery cell 11 measured when the reference charging voltage is reached, and i t1 may mean the amount of charging or charging current that has flowed during t1 hours.
[158]
In addition, the control unit 103 may be configured to calculate a resistance variation rate by comparing the calculated internal resistance with a pre-stored reference resistance. Here, the pre-stored reference resistance is a reference value for comparison with the current resistance of the battery cell 11 calculated by the control unit 103 and may be a value previously stored in the storage unit 105.
[159]
Preferably, the previously stored reference resistance may be the resistance of the battery cell 11 measured at a predetermined cycle time point. The control unit 103 may calculate a resistance variation rate as a ratio or difference of the resistance of the current battery cell 11 to the previously stored reference resistance.
[160]
For example, it is assumed that the reference resistance previously stored for the first battery cell C1 shown in FIG. 1 is A2[Ω]. In addition, based on the open circuit voltage of the first battery cell C1 measured by the voltage measuring unit 101 at the first point in time, the current resistance of the first battery cell C1 calculated by the control unit 103 is B2[ Ω]. The controller 103 may calculate the rate of change in resistance of the first battery cell C1 at the first point in time as a ratio of B2[Ω] to A2[Ω]. For example, the rate of change in resistance of the first battery cell C1 at the first point in time may be calculated by a calculation formula of “(B2 ÷ A2)×100”.
[161]
Preferably, the pre-stored reference resistance may include a reference resistance calculated based on the reference voltage pre-stored in the storage unit 105. That is, the pre-stored reference resistance corresponds to the pre-stored reference voltage, and is based on the open circuit voltage when the battery cell 11 is charged at a predetermined cycle and the voltage of the battery cell 11 reaches the reference charging voltage. It may be the calculated resistance. The previously stored reference resistance may be stored in the storage unit 105.
[162]
For example, the reference voltage A1[V] may be previously stored in the storage unit 105, and the reference resistance A2[Ω] calculated based on the reference voltage A1 may be previously stored.
[163]
Preferably, the previously stored resistance variation rate data may be configured to include the resistance variation rate calculated by the control unit 103 whenever the open circuit voltage is measured by the voltage measurement unit 101. That is, from after the predetermined cycle to before the present, the voltage measuring unit 101 may measure the open circuit voltage when the voltage of the battery cell 11 reaches the reference charging voltage by charging. Further, the control unit 103 calculates the current resistance based on the open circuit voltage measured by the voltage measurement unit 101, and according to the calculated current resistance and the reference resistance previously stored in the storage unit 105, the battery cell 11 ) Can be calculated. In addition, the calculated resistance variation rate may be included in the resistance variation rate data previously stored in the storage unit 105.
[164]
For example, in the embodiment shown in FIG. 1, the resistance change rate data previously stored for the first battery cell C1 includes the resistance change rate of the first battery cell C1 calculated at the first time point to the N-1 time point. I can. Here, N is an integer greater than or equal to 2, and when N is 2, only the resistance variation rate of the first battery cell C1 calculated at the first time point may be included in the previously stored resistance variation rate data. When the resistance change rate of the first battery cell C1 is calculated by the control unit 103 at the Nth time point, the resistance change rate of the first battery cell C1 calculated at the Nth time point is previously stored in the storage unit 105. It can be included in the resistance fluctuation rate data. In this case, the first to Nth resistance fluctuation rates may be included in the resistance fluctuation data previously stored in the storage unit 105.
[165]
The battery state estimation apparatus 100 according to an embodiment of the present invention may determine a resistance increase/decrease pattern of the current battery cell 11 based on the resistance change rate data previously stored in the storage unit 105 from a past time point to a current time point. . That is, the battery state estimation apparatus 100 according to an embodiment of the present invention may determine a resistance increase/decrease pattern of the current battery cell 11 based on pre-stored resistance change rate data that accumulates and stores the resistance change rate calculated in the past. . Further, since the battery state estimation apparatus 100 determines the degree of acceleration of deterioration of the current battery cell 11 based on the determined resistance increase/decrease pattern and the voltage increase/decrease pattern, the deterioration of the battery cell 11 only at the resistance change rate at a specific time There is an advantage in that it is possible to more accurately determine the degree of deterioration acceleration or degree of deterioration of the battery cell 11 than the case of determining the degree.
[166]
In addition, since the determined deterioration acceleration degree can be used as information for estimating the future state of the battery cell 11, the battery state estimating apparatus 100 according to an embodiment of the present invention includes the battery cell 11 There is an advantage of providing information that can estimate the future state based on the degree of acceleration of deterioration, as well as the past and present states of.
[167]
[168]
The control unit 103 may calculate a resistance change rate of a plurality of resistance change rates included within a predetermined number of cycles from the current cycle of the battery cell 11 from among the previously stored resistance change rate data. Here, the resistance rate of change may include an average rate of change or an instantaneous rate of change between resistance rates. Further, the plurality of resistance fluctuation rates included within a predetermined number of cycles from the current cycle may include a plurality of resistance fluctuation rates included within a preset number of cycles from the current cycle.
[169]
For example, the control unit 103 may calculate a resistance change rate of a plurality of resistance change rates included within 50 cycles from the current cycle. The calculation of the resistance change rate will be described in detail with reference to FIGS. 9 and 10.
[170]
9 is a diagram illustrating a resistance variation rate of a first battery cell calculated by an apparatus for estimating a battery state according to an exemplary embodiment of the present invention. 10 is a diagram illustrating a change rate of resistance of a second battery cell calculated by an apparatus for estimating a battery state according to an exemplary embodiment of the present invention.
[171]
9 and 10, the storage unit 105 stores resistance fluctuation data previously stored for the first battery cell C1 and resistance fluctuation data previously stored for the second battery cell C2 every cycle. I can.
[172]
Hereinafter, as shown in FIG. 9, a section including a preset number of cycles for the first battery cell C1 will be described as an In section. Similarly, as shown in FIG. 10, a section including a preset number of cycles for the second battery cell C2 will be described as a Jn section. Here, the In section shown in FIG. 9 may correspond to the In section shown in FIG. 3, and the Jn section shown in FIG. 10 may correspond to the Jn section shown in FIG. 4.
[173]
For example, it is assumed that the number of cycles preset to be included in one section is 50. In FIG. 9, if the current cycle of the first battery cell C1 is 300 cycles, the control unit 103 stores 251 to 300 cycles of the resistance change rate data previously stored for the first battery cell C1 in the storage unit 105. The resistance fluctuation rate of each cycle belonging to the included section I6 can be extracted. That is, the control unit 103 may calculate the resistance change rate of the period I6 by comparing the resistance change rates of each cycle belonging to the period I6 of the first battery cell C1 with each other.
[174]
Similarly, in FIG. 10, if the current cycle of the second battery cell C2 is 150 cycles, the control unit 103 includes 101 to 150 of the resistance change rate data previously stored for the second battery cell C2 in the storage unit 105. It is possible to extract the resistance fluctuation rate belonging to the J3 section including the cycle. The controller 103 may calculate the resistance change rate of the J3 period by comparing the resistance change rates of the cycles belonging to the J3 section of the second battery cell C2 with each other. Here, the resistance rate of change means a specific value for the rate of change.
[175]
Hereinafter, for convenience of explanation, if the resistance change rate is 0 or more, it will be described as a positive change rate, and if the resistance change rate is less than 0, it will be described as a negative change rate.
[176]
As in the example of calculating the voltage change rate described with reference to FIGS. 5 to 8 above, the control unit 103 calculates the resistance change rate between the resistance change rates included in the section to which the current cycle of the battery cell 11 belongs. By judging only one section, the resistance change rate may not be calculated. In addition, the control unit 103 may determine a cycle time point at which the resistance change rate changes from positive to negative or negative to positive, and divide a section to which the current cycle of the battery cell 11 belongs to a sub section based on the determined cycle time point. That is, the controller 103 may divide the one section into a plurality of sub-sections according to the resistance change rate of the resistance change rate belonging to one section, and calculate the resistance change rate for each of the divided sub-sections.
[177]
FIG. 11 is a diagram illustrating an enlarged view of a section of a variation rate of resistance of a first battery cell calculated by an apparatus for estimating a state of a battery according to an embodiment of the present invention.
[178]
For example, in the example of FIG. 11, the control unit 103 may calculate an average rate of change for continuous cycles included in section I1 or an instantaneous rate of change for continuous cycles included in section I1. Specifically, based on 10 cycles, the resistance change rate of the section I11 may be calculated as a negative rate of change, and the I12 resistance rate of change may be calculated as a positive rate of change. Accordingly, the controller 103 may divide the I1 section of the first battery cell C2 into an I11 section and an I12 section based on 10 cycles.
[179]
That is, in the embodiment of FIG. 11, the control unit 103 may divide the I1 section into I11 and I12 sections and calculate the resistance change rate for each of the I11 section and the I12 section. In this way, the controller 103 may divide one section into sub sections and calculate the resistance change rate for each sub section.
[180]
In this way, the battery state estimation apparatus 100 according to an embodiment of the present invention does not uniformly determine the section to which the current cycle of the battery cell 11 belongs to only one section, but divides the sub-sections depending on the case Since the rate of change is calculated in more detail, there is an advantage in that the current state of the battery cell 11 can be more accurately determined.
[181]
Also, the controller 103 may determine a resistance increase/decrease pattern based on the calculated resistance change rate. Here, the resistance increase/decrease pattern may include a resistance increase pattern and a resistance decrease pattern. In particular, when the calculated resistance change rate is a positive change rate, the control unit 103 may determine the resistance increase/decrease pattern as the resistance increase pattern. In addition, when the calculated resistance change rate is a negative change rate, the control unit 103 may determine the resistance increase/decrease pattern as the resistance decrease pattern.
[182]
For example, referring to FIGS. 9 and 11, when the current cycle of the first battery cell C1 belongs to the I1 section, the controller 103 is The rate of change of resistance can be calculated. When the current cycle of the first battery cell C1 belongs to the section I11, the control unit 103 may calculate the rate of change of the resistance of the section I11 to a value less than 0. That is, the rate of change of resistance of the section I11 may be calculated as a rate of change of negative. In addition, the controller 103 may determine a resistance increase/decrease pattern of the current first battery cell C1 as a resistance decrease pattern based on a result of calculating the resistance change rate as a negative change rate.
[183]
Conversely, when the current cycle of the first battery cell C1 belongs to the period I12, the control unit 103 may calculate the resistance change rate of the period I12 as a value of 0 or more. That is, the resistance change rate of the I12 section may be calculated as a positive change rate. The control unit 103 may determine a resistance increase/decrease pattern of the current first battery cell C1 as a resistance increase pattern based on a result of calculating the resistance change rate as a positive change rate. Similarly, even when the current cycle of the first battery cell C1 belongs to any one of I2 to I6, the control unit 103 may calculate the resistance change rate as a positive change rate based on the resistance change rate included in the corresponding section. . In addition, the controller 103 may determine a resistance increase/decrease pattern of the current first battery cell C1 as a resistance increase pattern based on a result calculated as a positive change rate.
[184]
As another example, referring to FIG. 10, when the current cycle of the second battery cell C2 belongs to any one of periods J1 to J6, the controller 103 The rate of change of resistance can be calculated. The control unit 103 may calculate a resistance change rate of a section in which the current cycle of the second battery cell C2 belongs to a value equal to or greater than 0. That is, the resistance change rate of the section in which the current cycle of the second battery cell C2 belongs may be calculated as the positive change rate. In addition, the controller 103 may determine a resistance increase/decrease pattern of the current second battery cell C2 as a resistance increase pattern based on the calculated resistance change rate.
[185]
In other words, the battery state estimation apparatus 100 according to an embodiment of the present invention determines the resistance increase/decrease pattern of the current battery cell 11 according to the calculated resistance change rate of the current cycle and the past resistance change rate stored in the previously stored resistance change rate data Therefore, there is an advantage of estimating the state of the battery cell 11 in consideration of not only the current state of the battery cell 11 but also the state of the past.
[186]
In addition, since the battery state estimation apparatus 100 according to an embodiment of the present invention calculates a resistance change rate of the battery cell 11 and determines a resistance increase/decrease pattern based on the calculated resistance change rate, the battery cell 11 It has the advantage of providing information that makes it easy to estimate the future state of the company.
[187]
[188]
When the resistance increase/decrease pattern is determined as the resistance increase pattern, the controller 103 may be configured to determine the degree of acceleration of deterioration of the battery cell 11 as either accelerated deterioration or linear deterioration according to the calculated resistance change rate. That is, when determining the resistance increase/decrease pattern as the resistance increase pattern, the controller 103 may determine the second degree of deterioration acceleration as either accelerated deterioration or linear deterioration.
[189]
In addition, when the resistance increase/decrease pattern is determined as the resistance decrease pattern, the control unit 103 may be configured to determine the degree of deterioration acceleration of the battery cell 11 as deceleration deterioration. That is, when determining the resistance increase/decrease pattern as the resistance decrease pattern, the controller 103 may determine the second degree of deterioration acceleration as only deceleration deterioration.
[190]
For example, in the embodiments of FIGS. 9 and 11, when the current cycle of the first battery cell C1 belongs to the period I11, the control unit 103 converts the resistance increase/decrease pattern of the first battery cell C1 into the resistance decrease pattern. You can decide. In addition, the control unit 103 may determine a second degree of deterioration acceleration of the first battery cell C1 as deceleration deterioration.
[191]
Conversely, if it belongs to any one of the current cycles I12 to I6 of the first battery cell C1, the controller 103 may determine the resistance increase/decrease pattern of the first battery cell C1 as the resistance increase pattern. In addition, the controller 103 may determine the degree of acceleration of the second deterioration of the first battery cell C1 as either accelerated deterioration or linear deterioration according to the resistance change rate of the section to which the first battery cell C1 belongs.
[192]
For another example, in the embodiment of FIG. 10, if the current cycle of the second battery cell C2 belongs to any one of the intervals J1 to J6, the control unit 103 determines the resistance increase/decrease pattern of the second battery cell C2. Can be determined as a pattern of increasing resistance. In addition, the controller 103 may determine the degree of acceleration of the second deterioration of the second battery cell C2 as either accelerated deterioration or linear deterioration, according to the resistance change rate of the section to which the second battery cell C2 belongs.
[193]
That is, in the charging situation of the battery cell 11, unlike the discharging situation, since the change factor of the resistance due to the open circuit voltage is not considered, the second degree of acceleration of deterioration may be determined based on the resistance increase/decrease pattern of the battery cell 11. In this case, the voltage increase/decrease pattern of the battery cell 11 may not be considered.
[194]
Therefore, the battery state estimation apparatus 100 according to an embodiment of the present invention determines the degree of acceleration of deterioration of the battery cell 11 based on the difference between the charging condition and the discharging condition, and thus the deterioration of the battery cell 11 There is an advantage of being able to determine specific state information on the degree of acceleration and degree of degeneration, and to provide the determined state information.
[195]
[196]
As described above, among the degrees of acceleration of deterioration of the battery cells 11, accelerated deterioration and linear deterioration can be classified according to how fast the deterioration of the battery cell 11 progresses. When the resistance increase/decrease pattern of the battery cell 11 is a resistance increase pattern, and the calculated resistance change rate is greater than or equal to a preset reference resistance change rate, the control unit 103 is configured to determine the degree of acceleration of deterioration of the battery cell 11 as accelerated deterioration. I can.
[197]
In addition, when the resistance increase/decrease pattern is a resistance increase pattern, and the calculated resistance change rate is less than a preset reference resistance change rate, the control unit 103 may be configured to determine a degree of deterioration acceleration of the battery cell 11 as linear degeneration.
[198]
Here, the preset reference resistance change rate is a reference rate of change for determining the degree of deterioration acceleration as either accelerated deterioration or linear deterioration when the resistance increase/decrease pattern of the battery cell 11 is determined as the resistance increase pattern. For example, the preset reference resistance change rate may be preset to increase the resistance change rate by 10% every 100 cycles.
[199]
For example, in the embodiments of FIGS. 9 and 11, it is assumed that the current cycle of the first battery cell C1 belongs to any one of periods I12 to I6, and the rate of change of resistance in the periods I12 to I6 is less than a preset reference resistance change rate. do. Since the resistance change rate of the section I12 to I6 is smaller than the preset reference resistance change rate, the control unit 103 may determine the second degree of acceleration of deterioration of the first battery cell C1 as linear degeneration.
[200]
As another example, in the embodiment of FIG. 10, it is assumed that the resistance change rate in the interval J1 to J3 is greater than or equal to the preset reference resistance change rate, and that the resistance change rate in the interval J4 to J6 is less than the preset reference resistance change rate. If the current cycle of the second battery cell C2 belongs to any one of the periods J1 to J3, the controller 103 determines the resistance change rate of the period to which the current cycle of the second battery cell C2 belongs to a preset reference resistance change rate and In comparison, the degree of acceleration of the second deterioration of the second battery cell C2 may be determined as the acceleration deterioration. Conversely, if the current cycle of the second battery cell C2 belongs to any one of the intervals J4 to J6, the control unit 103 determines the resistance change rate of the interval to which the current cycle of the second battery cell C2 belongs to a preset reference resistance. Compared with the rate of change, the degree of acceleration of the second deterioration of the second battery cell C2 may be determined as linear deterioration.
[201]
That is, the battery state estimation apparatus 100 according to an embodiment of the present invention does not uniformly determine the degree of deterioration acceleration for the resistance increase pattern, but compares the preset reference resistance change rate and the resistance change rate to accelerate the deterioration acceleration degree. It can be determined by subdividing into either degeneration or linear degeneration. Accordingly, there is an advantage that the current state of the battery cell 11 can be further subdivided and diagnosed in detail.
[202]
[203]
The control unit 103 may be configured to determine a resistance increase/decrease pattern of the battery cell 11 only when the calculated resistance variation rate exceeds a preset lower limit of resistance. That is, the control unit 103 determines the resistance increase/decrease pattern only when the resistance change rate of the battery cell 11 exceeds a preset lower limit of resistance, and determines the second deterioration acceleration degree of the battery cell 11 according to the determined resistance increase/decrease pattern. I can judge. For example, when the resistance fluctuation rate of the battery cell 11 is less than a preset lower limit value, the internal resistance of the battery cell 11 decreases below the reference value due to an electric short or the like, and the battery cell 11 is abnormally deteriorated. . Accordingly, the control unit 103 may determine a resistance increase/decrease pattern only when the battery cell 11 is normally deteriorated, except when the battery cell 11 is abnormally deteriorated due to external factors such as an electric attic.
[204]
If the classification of normal deterioration or abnormal deterioration of the battery cell 11 is not processed in advance, the degree of deterioration acceleration is determined according to the resistance increase or decrease pattern in the abnormal degeneration state, and the battery control condition is adjusted according to the determined deterioration acceleration degree. , There is a problem that may further deteriorate the state of the battery cell 11.
[205]
Therefore, the battery state estimation apparatus 100 according to an embodiment of the present invention determines the resistance increase/decrease pattern and the degree of acceleration of deterioration only when the state of the battery cell 11 is in a normal deterioration state, thereby deteriorating the battery cell 11. There is an advantage in that the time required for determining the acceleration degree can be shortened and the accuracy of the state determination of the battery cell 11 can be improved.
[206]
[207]
12 is a schematic diagram of a process of determining a degree of acceleration of deterioration of a battery cell based on a voltage change rate in the battery state estimation apparatus according to an embodiment of the present invention in a tree form.
[208]
Referring to FIG. 12, a first degree of acceleration of deterioration of the battery cell 11 may be determined according to a voltage increase/decrease pattern of the battery cell 11 determined by the controller 103. First, when the voltage fluctuation rate of the battery cell 11 calculated by the control unit 103 is less than or equal to a preset voltage lower limit value or more than a preset voltage upper limit value, it may be determined as abnormal deterioration. When it is determined that the battery cell 11 is abnormally deteriorated, the controller 103 may not determine a voltage increase/decrease pattern based on a voltage change rate.
[209]
That is, the control unit 103 is configured to determine the voltage increase/decrease pattern only when the voltage fluctuation rate of the battery cell 11 falls within the normal range, and to determine the first degree of deterioration acceleration of the battery cell 11 according to the determined voltage increase/decrease pattern. Can be.
[210]
When the voltage fluctuation rate of the battery cell 11 exceeds the preset voltage lower limit and is less than the preset voltage upper limit, the controller 103 determines the voltage increase/decrease pattern of the battery cell 11 based on the calculated voltage fluctuation rate and the previously stored voltage fluctuation data. I can. In addition, if the determined voltage increase/decrease pattern is a voltage decrease pattern, the controller 103 determines the degree of deterioration acceleration of the battery cell 11 as either acceleration deterioration or linear deterioration, and if the determined voltage increase/decrease pattern is a voltage increase pattern, the battery cell 11 The degree of deterioration acceleration of) can be judged as deceleration deterioration.
[211]
That is, if the determined voltage increase/decrease pattern is a voltage increase pattern, the controller 103 may determine the degree of deterioration acceleration of the battery cell 11 as only deceleration deterioration. Conversely, if the determined voltage increase/decrease pattern is a voltage decrease pattern, the control unit 103 compares the voltage change rate of the battery cell 11 and a preset reference voltage change rate to increase the degree of acceleration of the deterioration of the battery cell 11 by either acceleration degeneration or linear degeneration. It can be subdivided into one.
[212]
[213]
13 is a schematic diagram schematically illustrating a process of determining a degree of acceleration of deterioration of a battery cell based on a resistance change rate in the battery state estimation apparatus according to an embodiment of the present invention in a tree form.
[214]
Referring to FIG. 13, the controller 103 may determine the degree of acceleration of deterioration of the battery cell 11 only by the resistance increase/decrease pattern of the battery cell 11 regardless of the determined voltage increase/decrease pattern of the battery cell 11. That is, when determining the degree of acceleration of deterioration of the battery cell 11 in the charging situation of the battery cell 11, the voltage increase/decrease pattern and the resistance increase/decrease pattern of the battery cell 11 may not affect each other. However, in the discharge situation of the battery cell 11, since the open circuit voltage affects the factor of the internal resistance change of the battery cell 11, when the second degree of acceleration of deterioration is determined according to the resistance increase or decrease pattern, the voltage increase/decrease pattern is Can be considered.
[215]
When the resistance change rate of the battery cell 11 calculated by the control unit 103 is less than or equal to a preset lower limit of resistance, the control unit 103 may determine the deterioration state of the battery cell 11 as abnormal deterioration. When the deterioration state of the battery cell 11 is abnormal deterioration, the control unit 103 does not determine the degree of deterioration acceleration of the battery cell 11, but only in the case of normal degeneration, the degree of deterioration acceleration of the battery cell 11 I can judge.
[216]
When the resistance variation rate of the battery cell 11 calculated by the controller 103 exceeds a preset lower limit of resistance, the controller 103 may determine a resistance increase/decrease pattern based on the resistance variation rate of the battery cell 11. Here, when the resistance increase/decrease pattern of the battery cell 11 is determined as the resistance decrease pattern, the controller 103 may determine the second degree of deterioration acceleration of the battery cell 11 as only the deceleration deterioration. Conversely, when the resistance increase/decrease pattern of the battery cell 11 is determined as the resistance increase pattern, the controller 103 may determine the degree of acceleration of the deterioration of the battery cell 11 as either accelerated deterioration or linear deterioration based on the resistance change rate. have.
[217]
That is, only when the resistance increase/decrease pattern of the battery cell 11 is determined as the resistance increase pattern, the controller 103 is based on the resistance change rate of the section to which the current cycle of the battery cell 11 belongs. The current degree of acceleration of degeneration can be determined as either accelerated deterioration or linear degeneration.
[218]
The battery state estimation apparatus 100 according to an embodiment of the present invention may determine a history of a degree of deterioration of the battery cell 11, that is, a resistance change rate, as well as a degree of deterioration acceleration currently in progress and a degree of deterioration acceleration in the past. . Accordingly, the battery state estimation apparatus 100 has the advantage of being able to more accurately determine the current state of the battery cell 11 and to provide detailed information for predicting future conditions such as the life of the battery cell 11. have.
[219]
That is, the user obtains a first degree of deterioration acceleration according to a voltage increase/decrease pattern of the battery cell 11 and a second degree of degeneration acceleration according to the resistance increase/decrease pattern from the battery state estimation apparatus 100 according to an embodiment of the present invention. By doing so, it is possible to check the state of each battery cell 11 in more detail. Accordingly, the battery state estimation apparatus 100 determines the degree of deterioration acceleration of the battery cell 11 in various ways by using various indicators such as a voltage increase/decrease pattern and a resistance increase/decrease pattern, and provides the determined information to determine the state of the battery cell 11. It has the advantage of being able to provide specific and various information about
[220]
[221]
The battery pack 1000 according to the present invention may include the battery state estimation apparatus 100 according to the present invention described above. In addition, the battery pack 1000 according to the present invention may further include a battery cell, various electronic devices (including BMS, relays, fuses, etc.), and a pack case, in addition to the battery state estimation apparatus 100.
[222]
[223]
In addition, as another embodiment of the present invention, the battery state estimation apparatus 100 may be mounted on various devices that use electric energy, such as an electric vehicle and an energy storage system (ESS). In particular, the battery state estimation apparatus 100 according to the present invention may be included in an electric vehicle.
[224]
The electric vehicle according to the present invention may include the battery state estimation apparatus 100 according to the present invention. Here, the battery state estimation apparatus 100 may be included in the battery pack 1000, but may be implemented as a separate device from the battery pack 1000. For example, at least a part of the battery state estimation apparatus 100 may be implemented by an electronic control unit (ECU) of a vehicle.
[225]
In addition, the vehicle according to the present invention may include a vehicle body or electronic equipment commonly provided in a vehicle, in addition to the battery state estimation apparatus 100. For example, the vehicle according to the present invention may include a contactor, an inverter, a motor, one or more ECUs, etc., in addition to the battery state estimation apparatus 100 according to the present invention.
[226]
However, the present invention is not particularly limited to other components of a vehicle other than the battery state estimation apparatus 100.
[227]
[228]
The embodiments of the present invention described above are not implemented only through an apparatus and a method, but may be implemented through a program that realizes a function corresponding to the configuration of the embodiment of the present invention or a recording medium in which the program is recorded. Implementation can be easily implemented by an expert in the technical field to which the present invention belongs from the description of the above-described embodiment.
[229]
Although the present invention in the above has been described by the limited embodiments and drawings, the present invention is not limited thereto, and the technical idea of ​​the present invention and the following will be described by those of ordinary skill in the art to which the present invention pertains. It goes without saying that various modifications and variations are possible within the equivalent range of the claims.
[230]
In addition, the present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention to those of ordinary skill in the art. It is not limited by the drawings, and may be configured by selectively combining all or part of each embodiment so that various modifications may be made.
[231]
[232]
(Explanation of code)
[233]
10: battery module
[234]
11: battery cell
[235]
100: battery state estimation device
[236]
1000: battery pack
Claims
[Claim 1]
A voltage measuring unit that measures a voltage of a battery cell and measures an open circuit voltage of the battery cell whenever the measured voltage reaches a reference charging voltage; And receiving the open circuit voltage measured by the voltage measuring unit, calculating at least one of a voltage fluctuation rate or a resistance fluctuation rate based on a result of processing the received open circuit voltage, and when the voltage fluctuation rate is calculated, the calculated voltage Determine the voltage increase/decrease pattern based on the fluctuation rate and the previously stored voltage fluctuation data, and when the resistance fluctuation rate is calculated, determine the resistance increase or decrease pattern based on the calculated resistance fluctuation rate and the previously stored resistance fluctuation data And a control unit configured to determine a degree of acceleration of deterioration of the battery cell according to at least one of the patterns.
[Claim 2]
The method of claim 1, wherein, when both the voltage increase/decrease pattern and the resistance increase/decrease pattern are determined, the controller determines a first degree of deterioration acceleration of the battery cell based on the determined voltage increase/decrease pattern, and the determined resistance increase/decrease pattern And determining a second degree of deterioration acceleration of the battery cell independent of the first degree of deterioration acceleration based on the battery state estimation apparatus.
[Claim 3]
The method of claim 1, wherein the control unit is configured to calculate the voltage change rate by comparing the received open circuit voltage with a pre-stored reference voltage, and the pre-stored reference voltage is a voltage of the battery cell at a predetermined cycle time. It is configured to include the open circuit voltage when the reference charging voltage is reached, and the pre-stored voltage fluctuation data is a past calculated by the control unit each time the open circuit voltage is measured by the voltage measuring unit. Battery state estimation apparatus, characterized in that configured to include a voltage variation rate.
[Claim 4]
The method of claim 1, wherein the controller calculates a voltage change rate between the calculated voltage change rate and a plurality of voltage change rates included within a predetermined number of cycles from the current cycle of the battery cell among the pre-stored voltage change rate data, and the calculation And determining the voltage increase/decrease pattern based on the determined voltage change rate.
[Claim 5]
The method of claim 4, wherein, when the voltage increase/decrease pattern is determined as a voltage increase pattern, the controller is configured to determine a degree of deterioration acceleration of the battery cell as deceleration deterioration according to the calculated voltage change rate, and the voltage increase/decrease pattern is When the voltage decrease pattern is determined, the battery state estimation apparatus is configured to determine the degree of deterioration acceleration of the battery cell as either accelerated deterioration or linear deterioration.
[Claim 6]
The method of claim 5, wherein the control unit is configured to determine a degree of acceleration of deterioration of the battery cell as linear degeneration when the calculated voltage change rate is equal to or greater than a preset reference voltage change rate, and the calculated voltage change rate is a preset reference voltage When the rate of change is less than, the battery state estimation apparatus is configured to determine a degree of acceleration of deterioration of the battery cell as accelerated deterioration.
[Claim 7]
The apparatus of claim 1, wherein the controller is configured to determine the voltage increase/decrease pattern when the calculated voltage variation rate exceeds a preset voltage lower limit and is less than a preset voltage upper limit.
[Claim 8]
The method of claim 1, wherein the control unit is configured to calculate an internal resistance based on the received open circuit voltage, compare the calculated internal resistance with a pre-stored reference resistance to calculate a resistance change rate, and the pre-stored reference resistance Is configured to include a reference resistance calculated based on an open circuit voltage when the voltage of the battery cell reaches the reference charging voltage at a predetermined cycle time, the pre-stored resistance change rate data, the voltage measuring unit Each time the open circuit voltage is measured by, the battery state estimation apparatus is configured to include a past resistance variation rate calculated by the control unit.
[Claim 9]
The method of claim 1, wherein the control unit calculates a resistance change rate between the calculated resistance change rate and a plurality of resistance change rates included within a predetermined number of cycles from the current cycle of the battery cell among the previously stored resistance change rate data, and the calculation And determining the resistance increase/decrease pattern based on the determined resistance change rate.
[Claim 10]
The method of claim 9, wherein, when the resistance increase/decrease pattern is determined as a resistance increase pattern, the controller is configured to determine a degree of acceleration of deterioration of the battery cell as either accelerated deterioration or linear deterioration according to the calculated resistance change rate, When the resistance increase/decrease pattern is determined as the resistance decrease pattern, the battery state estimation apparatus is configured to determine a deterioration acceleration degree of the battery cell as a deceleration deterioration.
[Claim 11]
The method of claim 10, wherein the control unit is configured to determine a degree of acceleration of deterioration of the battery cell as an acceleration deterioration when the calculated resistance change rate is greater than or equal to a preset reference resistance change rate, and the calculated resistance change rate is a preset reference resistance If it is less than the rate of change, the battery state estimation apparatus, characterized in that configured to determine the degree of acceleration of deterioration of the battery cell as linear degeneration.
[Claim 12]
The apparatus of claim 1, wherein the controller is configured to determine the resistance increase/decrease pattern only when the calculated resistance variation rate exceeds a preset lower limit of resistance.
[Claim 13]
A battery pack comprising the apparatus for estimating a battery state according to any one of claims 1 to 12.
[Claim 14]
An electric vehicle comprising the battery state estimation apparatus according to any one of claims 1 to 12.