WO2014054548A1

WO2014054548A1 - Battery deterioration evaluation device, resistance value calculation device, battery deterioration evaluating method and program

Info

Publication number: WO2014054548A1
Application number: PCT/JP2013/076400
Authority: WO
Inventors: 和基尾▲崎▼; 一幸若杉; 克明森田; 重水　哲郎; 橋本　雅之
Original assignee: 三菱重工業株式会社
Priority date: 2012-10-02
Filing date: 2013-09-27
Publication date: 2014-04-10
Also published as: JP5960017B2; JP2014071098A

Abstract

A battery deterioration evaluation device provided with: a time detecting unit that detects a first time, at which the rate of change of a measured value, namely the current value and/or the voltage value of a secondary battery, reaches or falls below a prescribed rate of change, and a second time, at which the rate of change of the measured value reaches or falls below the prescribed rate of change, and the amount of change to the measured value since the first time reached or surpassed a prescribed amount of change; a resistance value calculating unit that calculates the internal resistance value of the secondary battery on the basis of the current value and the voltage value of the secondary battery at the first time, and the current value and the voltage value of the secondary battery at the second time; and a battery deterioration state evaluation unit that evaluates the deterioration state of the secondary battery on the basis of the internal resistance value of the secondary battery.

Description

Battery deterioration determination device, resistance value calculation device, battery deterioration determination method, and program

The present invention relates to a battery deterioration determination device, a resistance value calculation device, a battery deterioration determination method, and a program.
This application claims priority based on Japanese Patent Application No. 2012-220242 filed in Japan on October 2, 2012, the contents of which are incorporated herein by reference.

In various applications of secondary batteries, such as power systems that perform electrical control using the power stored in secondary batteries and automobiles equipped with secondary batteries, receive stable power supply from secondary batteries, and In order to reduce the battery replacement cost, it is desired to accurately determine the deterioration state of the secondary battery and replace the secondary battery at an appropriate time. Here, since the internal resistance value increases according to the deterioration of the secondary battery, the deterioration state of the secondary battery can be determined based on the internal resistance value of the secondary battery.

In relation to the determination of the deterioration state of the secondary battery, in the battery deterioration detection device described in Patent Document 1, the internal high value calculation unit inputs the current value input to and output from the secondary battery and the voltage applied to the secondary battery. The current internal resistance value of the secondary battery is calculated using the fluctuation range of the current value when the current value fluctuates more than a certain value and the fluctuation range of the voltage value at that time. Then, the battery deterioration information processing unit divides the current internal resistance value by the initial internal resistance value corresponding to the current temperature of the secondary battery, and the deterioration rate of the secondary battery at the current temperature of the secondary battery. And the deterioration rate is output to the monitor device.
Thereby, the battery degradation detection apparatus of patent document 1 can detect the degradation condition of a battery irrespective of the load pattern of a secondary battery.

International Publication WO2012 / 018028

When calculating the internal resistance value by measuring the current value or voltage value of the secondary battery, the calculated internal resistance value may vary depending on the power supply status of the secondary battery. For example, the timing at which the current value changes may deviate from the timing at which the voltage value changes, such as when the voltage value changes behind the current value in the secondary battery. Due to the difference in the change timing between the current value and the voltage value, a difference may occur in the internal resistance value calculated according to the measurement time of the current value or the voltage value, and the determination accuracy of the deterioration state of the secondary battery may be reduced. There is.

The present invention provides a battery deterioration determination device, a resistance value calculation device, a battery deterioration determination method, and a program capable of determining a deterioration state of a secondary battery with higher accuracy.

According to the first aspect of the present invention, in the battery deterioration determination device, the magnitude of the change rate of the measured value that is at least one of the current value or the voltage value of the secondary battery is equal to or less than the predetermined change rate. The magnitude of the change rate of the measurement value is equal to or less than a predetermined change rate at one time, and the magnitude of the change amount of the measurement value between the first time and the predetermined change amount is greater than or equal to the predetermined change amount. Based on the time detection unit that detects the second time, the current value and voltage value of the secondary battery at the first time, and the current value and voltage value of the secondary battery at the second time, A resistance value calculating unit that calculates an internal resistance value of the secondary battery; and a battery deterioration state determining unit that determines a deterioration state of the secondary battery based on the internal resistance value of the secondary battery.

According to the second aspect of the present invention, the battery deterioration determination device is the above-described battery deterioration determination device, and the time detection unit detects a plurality of combinations of the first time and the second time. The resistance value calculation unit calculates an internal resistance value of the secondary battery for each combination of the first time and the second time detected by the time detection unit, and calculates the internal resistance value obtained. An average value is obtained, and the battery deterioration state determination unit determines the deterioration state of the secondary battery based on the average value of the internal resistance values obtained by the resistance value calculation unit.

According to the third aspect of the present invention, the battery deterioration determination device is the above-described battery deterioration determination device, wherein the time detection unit has a predetermined rate of change in the current value of the secondary battery. And the time when the magnitude of the change rate of the voltage value of the secondary battery is not more than a predetermined change rate is detected as the first time, and the current value of the secondary battery And the change rate of the voltage value of the secondary battery is less than or equal to a predetermined change rate, and further, A time at which the amount of change in the current value of the secondary battery during the period is equal to or greater than a predetermined change is detected as the second time.

According to the fourth aspect of the present invention, in the resistance value calculating apparatus, the magnitude of the change rate of the measured value that is at least one of the current value or the voltage value of the secondary battery is equal to or less than the predetermined change rate. The magnitude of the change rate of the measurement value is equal to or less than a predetermined change rate, and the magnitude of the change amount of the measurement value between the first time and the first change time is a predetermined change amount. Based on the time detection unit that detects the second time, the current value and voltage value of the secondary battery at the first time, and the current value and voltage value of the secondary battery at the second time. And a resistance value calculation unit for calculating an internal resistance value of the secondary battery.

According to the fifth aspect of the present invention, the battery deterioration determination method is a battery deterioration determination method of the battery deterioration determination device, and a change in the measured value that is at least one of the current value or the voltage value of the secondary battery. The first time when the magnitude of the rate is less than or equal to a predetermined change rate, and the magnitude of the change rate of the measurement value is less than or equal to a predetermined change rate and the first time A time detection step of detecting a second time when the magnitude of the change amount of the measured value is greater than or equal to a predetermined change amount; a current value and a voltage value of the secondary battery at the first time; and a time at the second time A resistance value calculating step for calculating an internal resistance value of the secondary battery based on the current value and the voltage value of the secondary battery, and a deterioration of the secondary battery based on the internal resistance value of the secondary battery. Battery deterioration status judgment step Comprising a flop, the.

Further, according to the sixth aspect of the present invention, the program stores a predetermined rate of change in the measured value, which is at least one of the current value or the voltage value of the secondary battery, in the computer as the battery deterioration determination device. The first time when the change rate is less than or equal to the change rate of the measurement value is less than or equal to a predetermined change rate and the change amount of the measurement value between the first time and the change time A time detecting step for detecting a second time having a predetermined change amount or more, a current value and a voltage value of the secondary battery at the first time, and a current value of the secondary battery at the second time A resistance value calculating step for calculating an internal resistance value of the secondary battery based on the voltage value and a battery deterioration status for determining a degradation status of the secondary battery based on the internal resistance value of the secondary battery A determination step; Is a program for causing the line.

According to the above-described battery deterioration determination device, resistance value calculation device, battery deterioration determination method and program, the deterioration state of the secondary battery can be determined with higher accuracy.

It is a schematic block diagram which shows the function structure of the power supply system in one Embodiment of this invention. It is explanatory drawing which shows the example of 1st time and 2nd time which the time detection part in the embodiment detects. In the same embodiment, it is a flowchart which shows the process sequence in which a battery deterioration determination apparatus determines the necessity of replacement | exchange of a battery cell. It is explanatory drawing which shows the example of the change of the electric current value of the secondary battery in the same embodiment, and the change of a voltage value.

Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.
FIG. 1 is a schematic block diagram showing a functional configuration of a power supply system according to an embodiment of the present invention. In FIG. 1, the power supply system 1 includes a secondary battery system 100, a battery deterioration determination device 200, and a display device 300. The secondary battery system 100 includes a battery cell 110 and a BMU (Battery Management Unit) 120. The battery cell 110 includes a secondary battery 111 and a CMU (Cell Management Unit) 112. The battery deterioration determination device 200 includes a storage unit 210, a measurement value acquisition unit 220, a time detection unit 230, a resistance value calculation unit 240, and a battery deterioration state determination unit 250.

The secondary battery system 100 is connected to the power load 900 via the path W11 and supplies power to the power load 900. Here, the present embodiment can be applied to the secondary battery system 100 for various uses. For example, the secondary battery system 100 is installed in a stationary system such as a grid-connected smoothing power storage system used in combination with a power generation facility using natural energy such as wind power or sunlight, or a household power storage system. It may be provided. Alternatively, the secondary battery system 100 may be provided in a moving body such as an automobile or a train.

The battery cell 110 is a unit for replacing the battery in the secondary battery system 100 (that is, replaceable for each battery cell 110). The secondary battery system 100 includes one or more battery cells 110.
Here, the configuration of the battery cell 110 in the secondary battery system 100 may be arbitrary. For example, a plurality of battery cells 110 may be connected in series, may be connected in parallel, or a plurality of battery cells 110 connected in parallel may be connected in series.

The secondary battery 111 is a chargeable / dischargeable battery. The secondary battery 111 may be a battery whose internal resistance increases when it is deteriorated by repeated charge and discharge. For example, the secondary battery 111 may be a lithium ion battery or a lead battery.
The CMU 112 performs charge / discharge control and monitoring of the secondary battery 111 in units of cells. In particular, the CMU 112 detects the current value, voltage value, and temperature of the secondary battery 111 and notifies the battery deterioration determination device 200 via the BMU 120. Specifically, the battery cell 110 acquires a current value, a voltage value, and a temperature from a current sensor, a voltage sensor, and a temperature sensor provided in the secondary battery 111, respectively, as a measured value of the sensor at every predetermined sampling period. , Output to the BMU 120.

The BMU 120 communicates with a higher-level control device of the secondary battery system 100 to control and monitor the secondary battery system 100 as a whole. Further, the BMU 120 transmits the current value, voltage value, and temperature of the secondary battery 111 for each battery cell 110 detected by the CMU 112 to the battery deterioration determination device 200.

The battery deterioration determination device 200 calculates the internal resistance of the secondary battery 111 and determines whether or not the secondary battery 111 is deteriorated. The battery deterioration determination device 200 may be configured by a computer, or may be realized by dedicated hardware.
The storage unit 210 stores various data according to the control of the measurement value acquisition unit 220.
The measurement value acquisition unit 220 writes / reads various data to / from the storage unit 210. In particular, the measurement value acquisition unit 220 stores the current value, voltage value, and temperature of the secondary battery 111 for each battery cell 110 transmitted from the BMU 120 in the storage unit 210, and also calculates the time detection unit 230 and the resistance value. Data is read from the storage unit 210 and output in accordance with the processing of the unit 240.

The time detection unit 230 detects the first time and the second time for each battery cell 110 based on the current value of the secondary battery 111 detected by the CMU 112. Here, the first time is a time at which the magnitude of the rate of change of the measured value that is at least one of the current value or the voltage value of the secondary battery 111 is equal to or less than the predetermined rate of change. In the following, a case where a current value is used as a measured value will be described as an example. In addition, the second time here means that the change rate of the measurement value is equal to or less than a predetermined change rate, and the change amount of the measurement value between the first time and the predetermined change rate. It is a time that is more than the amount.

FIG. 2 is an explanatory diagram showing an example of the first time and the second time detected by the time detection unit 230. In the figure, a line L11 indicates the current value of the secondary battery 111, and a line L12 indicates the rate of change of the current value (hereinafter, the rate of change of the current value is referred to as “current rate of change”). Specifically, each point of the line L11 indicates the current value of the secondary battery 111 detected by the CMU 112 for each sampling period dts, and a line L11 is obtained by connecting the points. Each point of the line L12 indicates a difference obtained by subtracting the current value at the previous sampling from the current value of the secondary battery 111 for each sampling period, and the line L12 is obtained by connecting the points.

Here, in a transient state in which the current value is almost constant at a time before time T12 and at a time after time T14, and the current value is changing from time T12 to time T14. This is indicated by the line L12.
In the secondary battery 111, the timing at which the current value changes and the timing at which the voltage value change do not necessarily coincide with each other. Due to this timing shift, the ratio between the current value and the voltage value varies depending on the measurement timing.

Due to the difference in the ratio between the current value and the voltage value, the resistance value calculated based on the current value and the voltage value varies, and the accuracy of determining the deterioration status of the secondary battery 111 based on the resistance value is reduced. . In order to avoid such a decrease in determination accuracy, it is preferable to determine the deterioration status of the secondary battery 111 based on the current value and voltage value measured in the static state.
In order to accurately determine the deterioration state of the secondary battery 111, it is preferable to measure the current value and the voltage value at two times when there is a significant difference in the current value.

Therefore, the time detection unit 230 displays the time before the time T12 when the current value is in a steady state, and the time T14 after the time T14 when the current value is in a static state again after the current value has changed significantly from the time. The time of is detected. Hereinafter, the sampling time in the static state before the current value change is referred to as “previous time”, and the sampling time in the static state after the current value change is referred to as “post time”.

Specifically, the time detection unit 230 detects time T12 as the previous time from the sampling time when the storage unit 210 stores the current value and voltage value of the secondary battery 111 in the following procedure. Then, the time T15 is detected as a later time.
The combination of the previous time and the later time corresponds to an example of a combination of the first time and the second time. In the example of FIG. 2, the time T12 corresponds to an example of the first time, and the time T15 corresponds to an example of the second time.

In the following, the current value of the secondary battery 111 at the sampling time t is expressed as I (t), and the rate of change of the current value of the secondary battery 111 at the sampling time t is expressed as dI (t). As indicated by the line L12, here, it is calculated as dI (t) = I (t) −I (t−dts). In addition, as shown in FIG. 2, time dts shows a sampling period.

1. Among sampling times, a certain time is set as a candidate for a later time, and the current change rate at that time is calculated. Hereinafter, the set candidate is denoted as T15 ′. The current change rate at time T15 ′ is expressed as dI (T15 ′).
2. | DI (T15 ′) | ≦ dI_const (1)
It is determined whether or not the above is satisfied. Here, dI_const is a positive constant set in advance as a determination threshold value as to whether or not the current value is in a static state. || indicates an absolute value.

3. When the expression (1) is satisfied, the current change rate dI (T15'-dt1) before the time dt1 from the time T15 'is calculated. Here, the time dt1 is an assumed time of current rising. When the load fluctuation in the power load 900 is regular and the current rise time is constant, the time dt1 can be set in advance as a constant. Alternatively, the following processing may be performed for a plurality of times dt1, for example, the time detection unit 230 sets the time dt1 in the range from 1 sampling before 20 times before the time T15 '.

4). | DI (T15′−dt1) | ≧ dI_rise (2)
It is determined whether or not the above is satisfied. Here, dI_rise is a positive constant set in advance as a determination threshold value for determining whether or not the current is in a transient state.
5. When Expression (2) is satisfied, it is determined whether or not the current value is in a static state at all sampling times from time T15′-dt1 one time before time T15′-dt1-dts to time dt0. judge. In particular,
T15'-dt1-dt0≤t≤T15'-dt1-dts (3)
All sampling times t satisfying
| DI (t) | ≦ dI_const (4)
It is determined whether or not the above is satisfied. Here, the time dt1 is a positive constant set in advance as a settling time before the current rises.

6). When Expression (4) is satisfied, it is determined whether or not the current rising amount between time T15′-dt1-dts and time T15 ′ is a significant change amount. In particular,
I (T15 ′) − I (T15′−dt1-dts) ≧ dI_diff
... (5)
It is determined whether or not the above is satisfied. Here, dI_diff is a positive constant set in advance as a significant current value change threshold value for accurately determining the current value of the secondary battery 111.
7). When the expression (5) is satisfied, time T15′-dt1-dts is detected as the previous time, and time T15 ′ is detected as the subsequent time. For example, in the example shown in FIG. 2, the time detection unit 230 detects time T12 as the previous time and detects time T15 as the subsequent time.

Step 4 in the above procedure is a step for detecting the sampling time immediately before the current rise as the previous time, and is not an essential step.
In addition, the number of samplings for determining whether or not the state is a static state may be one or more before and after the current rise. Therefore, in step 5, it may be determined whether the current change rate is equal to or less than dI_const for only one sampling time. Further, in step 2, it may be determined whether the current change rate is equal to or less than dI_const for a plurality of sampling times.

Returning to FIG. 1, the resistance value calculation unit 240 is based on the current value and voltage value of the secondary battery 111 at the first time and the current value and voltage value of the secondary battery 111 at the second time. An internal resistance value of 111 is calculated. For example, in the example illustrated in FIG. 2, the resistance value calculation unit 240 performs a secondary operation based on the difference between the current value and voltage value at time T12, which is the previous time, and the current value and voltage value at time T15, which is the subsequent time. The internal resistance value of the battery 111 is calculated, and the temperature of the internal resistance value is corrected based on the temperature of the secondary battery 111.
In addition, when the influence of the temperature change of the secondary battery 111 can be disregarded, such as when the secondary battery system 100 is installed indoors where the air conditioning equipment is operating, the resistance value calculation unit 240 does not perform temperature correction. It may be.

Battery deterioration state determination unit 250 determines the deterioration state of secondary battery 111 based on the internal resistance value of secondary battery 111 after temperature correction acquired by resistance value calculation unit 240. For example, the battery deterioration state determination unit 250 compares the internal resistance value of the secondary battery 111 after temperature correction with a predetermined threshold value, and the battery cell 110 needs to be replaced when the internal resistance value is equal to or greater than the threshold value (secondary battery It is determined that the degree of deterioration of the battery 111 is large). On the other hand, when the internal resistance value is less than the threshold value, the battery deterioration state determination unit 250 determines that the replacement of the battery cell 110 is unnecessary (the degree of deterioration of the secondary battery 111 is small).

The display device 300 has a display screen such as a liquid crystal panel or an organic EL (Organic Electroluminescence) panel, for example, and displays the determination result of the battery deterioration state determination unit 250.
However, the display device 300 only needs to be able to notify the determination result of the battery deterioration state determination unit 250. For example, the display device 300 may include a lamp such as a light-emitting diode, and turn on the lamp to display that the secondary battery 111 needs to be replaced. Alternatively, the display device 300 outputs a sound such as a voice message or a buzzer sound in addition to or instead of the visual display to indicate that the secondary battery 111 needs to be replaced. You may do it.

Next, the operation of the battery deterioration determination device 200 will be described with reference to FIG.
FIG. 3 is a flowchart illustrating a processing procedure in which the battery deterioration determination device 200 determines whether or not the battery cell 110 needs to be replaced. The battery deterioration determination device 200 is illustrated for each of the battery cells 110 periodically, for example, every day or every month, or in response to a request from a user of the battery deterioration determination device 200 (for example, an administrator of the power supply system 1). Process 3 is performed. Note that the battery deterioration determination device 200 may perform the processing of FIG. 3 in real time for each sampling period of the current value, voltage value, and temperature of the secondary battery 111.

In the process of FIG. 3, first, the time detection unit 230 initially sets a candidate for a later time (step S101). For example, the time detection unit 230 sets any of the sampling times when the storage unit 210 stores the current value of the secondary battery 111 or the like as a later time candidate. In addition, when the battery deterioration determination apparatus 200 performs the process of FIG. 3 for each current value, voltage value, and temperature sampling period of the secondary battery 111, the time detection unit 230 sets the latest sampling time as a candidate for a later time. Set.

Next, the time detection unit 230 determines whether or not the storage unit 210 stores data at the sampling time that is a determination target of the static state before rising (step S102). For example, in the example shown in FIG. 2, the time detection unit 230 determines whether the storage unit 210 stores data at each sampling time from time T11 to time T12.

When it is determined that the corresponding data is stored in the storage unit 210 (step S102: YES), the time detection unit 230 calculates a current change rate in a later time candidate (step S111). Step 1 of the process described above with reference to FIG. 2 (hereinafter referred to as “the above process”) corresponds to an example of steps S101 and S111 of FIG.

Next, the time detection unit 230 determines whether or not the current value of the secondary battery 111 is in a static state in a later time candidate based on the current change rate calculated in step S111 (step S112). Step 2 of the above process corresponds to an example of step S112 in FIG.
When it determines with it being in a static state (step S112: YES), the time detection part 230 calculates the electric current change rate in the assumption time of an electric current value rise start (step S121). Step 3 of the above process corresponds to an example of step S121 in FIG.

Next, based on the current change rate calculated in step S121, the time detection unit 230 determines whether or not the current actually rises at the estimated current value rise start time (step S122). Step 4 of the above process corresponds to an example of step S122 in FIG.
When it is determined that the current is rising (step S122: YES), the time detection unit 230 calculates a current change rate for each sampling time that is a determination target of the static state before the rising (step S131).

Then, based on the current change rate calculated in step S131, the time detection unit 230 sets the current value of the secondary battery 111 to the static state at all the sampling times that are targets for determination of the static state before rising. It is determined whether or not there is (step S132). Step 5 of the above process corresponds to an example of steps S131 to S132 in FIG.
When it is determined that it is in a static state (step S132: YES), the time detection unit 230 subtracts the current value in the candidate at the later time from the current value in the candidate at the previous time as the current change amount due to the rising of the current. The amount of change is calculated (step S141).

Next, the time detection unit 230 determines whether or not the change amount calculated in step S141 is a significant current value change amount for accurately determining the current value of the secondary battery 111 (step S142). Step 6 of the above process corresponds to an example of step S142 in FIG.
When it is determined that the current value change amount is significant (step S142: YES), the time detection unit 230 sets the previous time candidate as the previous time, sets the subsequent time candidate as the subsequent time, The time and the later time are output to the resistance value calculation unit 240 (step S151). Step 7 of the above process corresponds to an example of step S151 in FIG.

Next, the resistance value calculation unit 240 calculates the internal resistance value of the secondary battery 111 based on the previous time and the later time set by the time detection unit 230 (step S152). And the resistance value calculation part 240 correct | amends an internal resistance value based on the temperature of the secondary battery 111, and outputs the internal resistance value after correction | amendment to the battery degradation condition determination part 250 (step S153).
Then, the battery deterioration state determination unit 250 determines the deterioration state of the secondary battery 111 based on the corrected internal resistance value, and outputs the determination result to the display device 300 (step S154).
Thereafter, the process of FIG. 3 is terminated.

On the other hand, when it is determined in step S102 that the corresponding data is not stored in the storage unit 210 (step S102: NO), the time detection unit 230 changes the later time candidate (step S161). For example, the time detection unit 230 sets a sampling time that has not yet been set as a later time candidate among the sampling times at which the storage unit 210 stores data as a later time candidate.
After step S161, the process returns to step S102.

When there is no sampling time that has not yet been set as a later time candidate, or when the battery deterioration determination device 200 performs the process of FIG. 3 for each sampling period of the current value, voltage value, or temperature of the secondary battery 111. Then, the battery deterioration determination device 200 ends the process of FIG. In this case, the battery deterioration determination device 200 fails to determine the deterioration state of the secondary battery 111, and waits for the storage unit 210 to store new data, for example, and performs the process of FIG. 3 again.

Moreover, also when it determines with the electric current value of the secondary battery 111 not being in a static state in step S112 (step S112: NO), it progresses to step S161.
If it is determined in step S122 that the current has not risen at the estimated start time of the current value rise (step S122: NO), the process also proceeds to step S161.
Moreover, also when it determines with the electric current value of the secondary battery 111 not being in a static state in step S132 (step S132: NO), it progresses to step S161.
If it is determined in step S142 that the amount of change calculated in step S141 is not a significant current value change amount (step S142: NO), the process also proceeds to step S161.

As described above, the time detection unit 230 determines that the current value of the secondary battery 111 is in a static state, the current value of the secondary battery 111 is in a static state, and the first time. The second time at which the magnitude of the change amount of the current value during the period is equal to or greater than the predetermined change amount is detected.
Thereby, the resistance value calculation unit 240 determines whether the internal value of the secondary battery 111 is based on the current value and the voltage value at two times when the current value is in a static state and the current value is significantly different. The value can be calculated with higher accuracy, and the battery deterioration state determination unit 250 can determine the deterioration state of the secondary battery 111 with higher accuracy using the internal resistance value.

In the above description, the time detection unit 230 detects the static state after the current rise after detecting the static state after the current rise, but conversely, the static state before the current rise is detected. You may make it detect the static state after electric current rise after detecting.
In the above description, the time detection unit 230 detects the sampling time in the static state before and after the current rise. However, the time detection unit 230 detects the sampling time in the static state before and after the current fall. You may do it.
When the entire secondary battery system 100 is replaced when the secondary battery 111 is deteriorated, the battery deterioration determination device 200 determines the deterioration state by obtaining the internal resistance value of the secondary battery 111 for the entire secondary battery system 100. It may be.

Moreover, the battery deterioration determination device 200 calculates the internal resistance value of the secondary battery 111 a plurality of times to obtain an average, and determines the deterioration state of the secondary battery 111 based on the obtained average value of the internal resistance values. You may do it.
In this case, the time detection unit 230 detects a plurality of combinations of the first time and the second time. And the resistance value calculation part 240 calculates the internal resistance value of the secondary battery 111 for every combination of the 1st time detected by the time detection part 230, and the 2nd time, and average value of the obtained internal resistance value Ask for. Then, the battery deterioration state determination unit 250 determines the deterioration state of the secondary battery 111 based on the average value of the internal resistance values obtained by the resistance value calculation unit 240.
Thereby, the battery deterioration determination device 200 determines the internal resistance value with higher accuracy by reducing the influence of the temporary measurement error of the sensor and external noise, and determines the deterioration state of the secondary battery 111 with higher accuracy. be able to.

Further, the case where the time detection unit 230 detects the sampling time when the current value of the secondary battery 111 is stabilized has been described above. However, the time detection unit 230 stabilizes the current value of the secondary battery 111. In addition to or instead of the state, the sampling time in the static state of the voltage value of the secondary battery 111 may be detected.

Here, FIG. 4 is an explanatory diagram showing an example of a change in the current value and a change in the voltage value of the secondary battery 111. In the figure, a line L21 indicates a change in the current value of the secondary battery 111, and a line L22 indicates a change in the voltage value of the secondary battery 111. In the example shown in FIG. 4, the current value of the secondary battery 111 is in a static state during the period from time T21 to T22. On the other hand, the voltage value of the secondary battery 111 continues to change after time T21 and is not in a static state. Thus, the timing at which the current value changes may not match the timing at which the voltage value changes.

In this case, even when the current value is in a static state, the voltage value varies depending on the sampling time, and the resistance value calculated by the battery deterioration determination device 200 (resistance value calculation unit 240) varies, and the two values based on the resistance value are generated. The accuracy of determining the deterioration status of the secondary battery 111 is reduced. In order to avoid such a decrease in determination accuracy, the time detection unit 230 detects the sampling time in the state where the voltage value of the secondary battery 111 is stabilized in addition to or instead of the state where the current value of the secondary battery 111 is stabilized. You may make it do.

For example, in the time detection unit 230, the magnitude of the change rate of the current value of the secondary battery 111 is equal to or less than a predetermined change rate, and the magnitude of the change rate of the voltage value of the secondary battery 111 is a predetermined change. A time that is lower than the rate is detected as one time. In addition, the time detection unit 230 has a change rate of the current value of the secondary battery 111 equal to or less than a predetermined change rate, and a change rate of the voltage value of the secondary battery 111 has a predetermined change. The time when the amount of change in the current value of the secondary battery 111 between the first time and the first time is equal to or greater than a predetermined change is detected as the second time.

As a result, the resistance value calculation unit 240 determines the secondary value based on the current value and the voltage value at two times when the voltage value is in a static state in addition to the current value and there is a significant difference in the current value. The internal resistance value of the battery 111 can be calculated with higher accuracy, and the battery deterioration state determination unit 250 can determine the deterioration state of the secondary battery 111 with higher accuracy using the internal resistance value.

In addition, you may make it the time detection part 230 switch itself whether it detects the steady state of a voltage value. For example, when the time detection unit 230 determines whether both the current value and the voltage value of the secondary battery 111 are in a static state, the first time and the second time are detected for a predetermined time or more. If it fails, it may be switched to the determination of whether or not the current value is in a static state. That is, the time detection unit 230 may not determine whether the voltage value is in a static state.
Thereby, the time detection unit 230 can detect the first time and the second time.
Note that, among the units of the battery deterioration determination device 200, the storage unit 210, the measurement value acquisition unit 220, the time detection unit 230, and the resistance value calculation unit 240 may constitute a resistance value calculation device.

As described above, a computer can be used as the battery deterioration determination device 200. Therefore, a program for realizing all or a part of the functions of the battery deterioration determination apparatus 200 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed. You may process each part by. Here, the “computer system” includes an OS and hardware such as peripheral devices.
Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM or a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like without departing from the gist of the present invention.

The present invention provides the first time when the magnitude of the change rate of the measured value that is at least one of the current value or the voltage value of the secondary battery is equal to or less than the predetermined change rate, and the magnitude of the change rate of the measured value. A time detection unit for detecting a second time when the second change time is less than or equal to a predetermined change rate and the magnitude of the change amount of the measured value between the first time and the predetermined change amount The resistance value for calculating the internal resistance value of the secondary battery based on the current value and voltage value of the secondary battery at the first time and the current value and voltage value of the secondary battery at the second time The present invention relates to a battery deterioration determination device including a calculation unit and a battery deterioration state determination unit that determines a deterioration state of the secondary battery based on an internal resistance value of the secondary battery.
According to the present invention, it is possible to determine the deterioration state of the secondary battery with higher accuracy.

1 power supply system 100 secondary battery system 110 battery cell 111 secondary battery 112 CMU
120 BMU
200 Battery Degradation Determination Device 210 Storage Unit 220 Measurement Value Acquisition Unit 230 Time Detection Unit 240 Resistance Value Calculation Unit 250 Battery Degradation State Determination Unit 300 Display Device 900 Power Load

Claims

The first time when the magnitude of the change rate of the measured value that is at least one of the current value or the voltage value of the secondary battery is equal to or less than the predetermined change rate, and the magnitude of the change rate of the measured value is a predetermined value A time detection unit that detects a second time that is equal to or less than a change rate and has a magnitude of a change amount of the measured value between the first time and a predetermined change amount;
Resistance value calculation for calculating the internal resistance value of the secondary battery based on the current value and voltage value of the secondary battery at the first time and the current value and voltage value of the secondary battery at the second time And
A battery deterioration state determination unit for determining a deterioration state of the secondary battery based on the internal resistance value of the secondary battery;
A battery deterioration determination device comprising:
The time detection unit detects a plurality of combinations of the first time and the second time,
The resistance value calculation unit calculates an internal resistance value of the secondary battery for each combination of the first time and the second time detected by the time detection unit, and an average value of the obtained internal resistance values Seeking
The battery deterioration state determination unit determines a deterioration state of the secondary battery based on an average value of the internal resistance values obtained by the resistance value calculation unit.
The battery deterioration determination device according to claim 1.
In the time detection unit, the magnitude of the change rate of the current value of the secondary battery is equal to or less than a predetermined change rate, and the magnitude of the change rate of the voltage value of the secondary battery is equal to or less than the predetermined change rate. Is detected as the first time, the magnitude of the rate of change of the current value of the secondary battery is equal to or less than a predetermined rate of change, and the rate of change of the voltage value of the secondary battery is The time when the magnitude is less than or equal to a predetermined change rate, and the magnitude of the change amount of the current value of the secondary battery between the first time and the predetermined change quantity is greater than or equal to the predetermined change amount. The battery deterioration determination device according to claim 1, which is detected as two times.
The first time when the magnitude of the change rate of the measured value that is at least one of the current value or the voltage value of the secondary battery is equal to or less than the predetermined change rate, and the magnitude of the change rate of the measured value is a predetermined value A time detection unit that detects a second time that is equal to or less than a change rate and has a magnitude of a change amount of the measured value between the first time and a predetermined change amount;
Resistance value calculation for calculating the internal resistance value of the secondary battery based on the current value and voltage value of the secondary battery at the first time and the current value and voltage value of the secondary battery at the second time And
A resistance value calculation device comprising:
A battery deterioration determination method for a battery deterioration determination device,
The first time when the magnitude of the change rate of the measured value that is at least one of the current value or the voltage value of the secondary battery is equal to or less than the predetermined change rate, and the magnitude of the change rate of the measured value is a predetermined value A time detection step of detecting a second time that is equal to or less than a change rate and has a magnitude of a change amount of the measurement value between the first time and a predetermined change amount;
Resistance value calculation for calculating the internal resistance value of the secondary battery based on the current value and voltage value of the secondary battery at the first time and the current value and voltage value of the secondary battery at the second time Steps,
A battery deterioration state determination step for determining a deterioration state of the secondary battery based on the internal resistance value of the secondary battery;
A battery deterioration determination method comprising:
To a computer as a battery deterioration determination device,
The first time when the magnitude of the change rate of the measured value that is at least one of the current value or the voltage value of the secondary battery is equal to or less than the predetermined change rate, and the magnitude of the change rate of the measured value is a predetermined value A time detection step of detecting a second time that is equal to or less than a change rate and has a magnitude of a change amount of the measurement value between the first time and a predetermined change amount;
Resistance value calculation for calculating the internal resistance value of the secondary battery based on the current value and voltage value of the secondary battery at the first time and the current value and voltage value of the secondary battery at the second time Steps,
A battery deterioration state determination step for determining a deterioration state of the secondary battery based on the internal resistance value of the secondary battery;
A program for running