JP6831807B2 - Data processing device and diagnostic method - Google Patents

Description

The present invention relates to a data processing device and a diagnostic method, for example, a data processing device for monitoring the state of a lead storage battery, and a diagnostic method for diagnosing a deteriorated state of the lead storage battery.

Lead-acid batteries deteriorate in capacity due to repeated charging and discharging for a long period of time. In a power storage system using a lead-acid battery, recovery charging is periodically performed to fully charge the lead-acid battery in order to remove sulfation, which is one of the causes of deterioration of the lead-acid battery.

As a recovery charging method, a constant current-constant voltage charging (CCCV) method and a multi-stage charging method are known. In the constant current-constant voltage charging method, first charging with a constant current value (hereinafter, also referred to as "constant current charging" or "CC charging") is performed, and after the storage battery voltage reaches a predetermined threshold value, the constant current charging method is performed. This is a charging method in which a lead storage battery is restored to a fully charged state by charging with a voltage (hereinafter, also referred to as “constant voltage charging” or “CV charging”). In the multi-stage charging method, constant current charging is performed first, and after the storage battery voltage reaches a predetermined threshold, constant current charging at a current value lower than the previous current value is repeated a plurality of times, and finally, a predetermined current value is applied. It is a charging method that restores the lead-acid battery to a fully charged state by performing constant voltage charging with voltage. In both charging methods, constant voltage charging is performed in the latter half of recovery charging.

Further, in the power storage system using the lead storage battery, the deterioration state of the lead storage battery is determined.
As a method of diagnosing the deterioration state of the lead-acid battery, a method of measuring the internal resistance of the lead-acid battery and estimating the life of the lead-acid battery from the measurement result, or until the remaining capacity is exhausted after the lead-acid battery is fully charged (discharge termination). A method (capacity test) of discharging (up to a voltage) and integrating the discharge current to measure the actual capacity is known.

Further, in Patent Document 1, as a method of diagnosing a deteriorated state of a lead-acid battery, an internal timer is driven when the voltage of the lead-acid battery exceeds a predetermined upper limit voltage value at the time of recovery and charging of the lead-acid battery, and the charging current value of the lead-acid battery is increased. A method of terminating the operation of the internal timer when the current value becomes equal to or less than a predetermined lower limit current value and calculating the complete discharge capacity of the lead-acid battery based on the time measured by the internal timer is disclosed.

Japanese Patent No. 4272403

However, the above-mentioned conventional method for diagnosing a deteriorated state of a lead storage battery has the following problems.
For example, in the method of measuring the internal resistance of a lead storage battery, it is necessary to separately install dedicated sensors in each cell of the lead battery in order to measure the internal resistance.

Further, in the capacity test, the lead-acid battery needs to be fully charged, completely discharged, and fully charged again, and the operation of the power storage system needs to be stopped for a long time.

Further, the diagnostic method disclosed in Patent Document 1 is difficult to apply to a power storage system that performs recovery charging of a multi-stage charging method in which the storage battery voltage becomes equal to or higher than the upper limit voltage value multiple times before starting constant voltage charging. is there.

As described above, since the conventional method for diagnosing the deterioration state of the lead storage battery has various problems, the inventors of the present application have considered that a new deterioration determination technique for the lead storage battery is required.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to make it easier to diagnose a deteriorated state of a lead storage battery regardless of a recovery charging method.

The data processing device according to the typical embodiment of the present invention relates to a measurement value acquisition unit that acquires a measurement value of the charging current in the constant voltage charging period of the recovery charging of the lead storage battery, and a charging current in the constant voltage charging period. A storage unit that stores correspondence data that represents the correspondence between the first parameter and the second parameter that indicates the degree of deterioration of the lead-acid battery, the measurement value acquired by the acquisition unit, and the storage unit stored in the storage unit. It is characterized by having a determination unit for determining a deteriorated state of the lead storage battery based on the correspondence data.

According to the data processing device according to the present invention, it is possible to more easily diagnose the deteriorated state of the lead storage battery regardless of the recovery charging method.

It is a figure which shows the relationship between the charge / discharge cycle number of a lead storage battery, and the recovery charge terminal current. It is a figure which shows the relationship between the charge / discharge cycle number of a lead storage battery, and the storage battery capacity. It is a figure which shows the relationship between the recovery end charge current of a lead storage battery, and the storage battery capacity. It is a figure which shows the relationship between the charge / discharge cycle number of a lead storage battery, and the charge current convergence time. It is a figure which shows the structure of the power storage system which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the monitoring apparatus which concerns on Embodiment 1. FIG. It is a flowchart which shows the flow of the diagnostic method for diagnosing the deterioration state of the lead storage battery which concerns on Embodiment 1. It is a timing chart which shows the charge current and the storage battery voltage of the lead storage battery at the time of recovery charge. It is a figure which shows the structure of the monitoring apparatus which concerns on Embodiment 2. FIG. It is a flowchart which shows the flow of the diagnostic method for diagnosing the deterioration state of the lead storage battery which concerns on Embodiment 2. It is a timing chart which shows the charge current and the storage battery voltage of the lead storage battery at the time of recovery charge. It is a figure which shows the structure of the monitoring apparatus which concerns on Embodiment 3. It is a flowchart which shows the flow of the diagnostic method for diagnosing the deterioration state of the lead storage battery which concerns on Embodiment 3. It is a timing chart which shows the charge current and discharge current of the lead storage battery at the time of recovery charge. It is a figure which shows the characteristic of the charge current in recovery charge. It is a figure which shows an example of the case where the function representing the change with respect to time of the charging current in the constant voltage charging period of recovery charge is displayed by the semi-logarithmic graph. It is a figure which shows the structure of the monitoring apparatus which concerns on Embodiment 4. FIG. It is a figure which shows the relationship between the time constant B and the storage battery capacity. It is a flowchart which shows the flow of the diagnostic method for diagnosing the deterioration state of the lead storage battery which concerns on Embodiment 4.

1. 1. Outline of Embodiment First, an outline of a typical embodiment of the invention disclosed in the present application will be described. In the following description, as an example, reference numerals on drawings corresponding to the components of the invention are described in parentheses.

[1] The data processing apparatus (1,1A to 1C) according to the typical embodiment of the present invention acquires the measured value (131) of the charging current in the constant voltage charging period of the recovery charging of the lead storage battery (7). Correspondence data (132, 132A, 132C) showing the correspondence between the measured value acquisition unit (12) and the first parameter regarding the charging current during the constant voltage charging period and the second parameter indicating the degree of deterioration of the lead storage battery. Based on the storage unit (13) that stores the lead-acid battery, the measured value acquired by the acquisition unit, and the correspondence data stored in the storage unit, the determination unit (14) that determines the deterioration state of the lead-acid battery. , 14A-14C), and so on.

[2] In the data processing device (1), the first parameter is a recovery charging end-stage current indicating a charging current at the end of the constant-voltage charging period, and the determination unit (14) is used for the constant-voltage charging. The measured value of the charging current when a predetermined time (t1) elapses after the charging current falls below the predetermined threshold (Ith) in the period is used as the measured value of the recovery charging end stage current, and the measured value and the corresponding relationship data are used. The deterioration state of the lead storage battery may be determined based on the above.

[3] In the data processing device (1A), the first parameter is a second threshold value (Ith2) smaller than the first threshold value after the charging current reaches the first threshold value (Ith1) during the constant voltage charging period. ) Is the charging current convergence time indicating the time until the charging current reaches the first threshold value, and the determination unit (14A) reaches the second threshold value after the charging current reaches the first threshold value during the constant voltage charging period. A determination processing unit (140A) that determines the deterioration state of the lead-acid battery based on the time measuring unit (140A) that measures the time until (t2), the measured value of the time measured by the time measuring unit, and the correspondence data. 141A) and may be included.

[4] In the data processing device (1B), the first parameter is a recovery charging end-stage current indicating a charging current at the end of the constant-voltage charging period, and the measured value acquisition unit charges the lead storage battery. The determination unit (14B) acquires the current and the discharge current of the lead storage battery, and the determination unit (14B) integrates the charge current integration unit (142) for calculating the integrated value of the charge current of the lead storage battery and the discharge current of the lead storage battery. The discharge current integrating unit (143) that calculates the value, and the integrated value of the charging current after the completion of the recovery charging performed last time and the integrated value of the discharge current after the completion of the recovery charging performed last time. The measured value of the charging current of the lead storage battery when the ratio reaches a predetermined value is used as the measured value of the recovery charging end-stage current, and the deterioration state of the lead storage battery is determined based on the measured value and the corresponding relationship data. The determination processing unit (141B) to be used may be included.

[5] In the data processing device (1C), the determination unit determines the change of the charging current in the constant voltage charging period with respect to the time based on the elapsed time in the constant voltage charging period and the measured value of the charging current. The lead-acid battery is based on the function estimation unit (144) that estimates the function shown (Equation (1)), the first parameter calculated based on the function estimated by the function estimation unit, and the correspondence data. The determination processing unit (141C) for determining the deterioration state of the above may be included.

[6] The method for determining the deteriorated state of the lead-acid battery according to a typical embodiment of the present invention includes a measurement value acquisition step for acquiring a measurement value of a charging current during a constant voltage charging period for recovery charging of the lead-acid battery. Correspondence representing the correspondence relationship between the measured value acquired by the measured value acquisition step, the first parameter regarding the charging current in the constant voltage charging period stored in the storage unit, and the second parameter indicating the degree of deterioration of the lead storage battery. It is characterized by including a determination step of determining a deteriorated state of the lead storage battery based on the relational data.

[7] In the above diagnostic method, the first parameter is a recovery charging end-stage current indicating a charging current at the end of the constant-voltage charging period, and in the determination step, the charging current is predetermined in the constant-voltage charging period. The measured value of the charging current when a predetermined time elapses after the voltage drops below the threshold value is used as the measured value of the recovery charging end-stage current, and the deterioration state of the lead-acid battery is determined based on the measured value and the corresponding relationship data. It is characterized by including steps.

[8] In the above diagnostic method, the first parameter indicates the time from when the charging current reaches the first threshold value to when it reaches the second threshold value smaller than the first threshold value during the constant voltage charging period. The determination step is a current convergence time, which is a time measuring step for measuring the time from when the charging current reaches the first threshold value to when the charging current reaches the second threshold value during the constant voltage charging period, and the time measuring step. The determination processing step of determining the deterioration state of the lead storage battery may be included based on the measured value of the time measured by the above and the correspondence data.

[9] In the above diagnostic method, the first parameter is a recovery charging end-stage current indicating a charging current at the end of the constant-voltage charging period, and the measured value acquisition step is a charging current and a discharging current of the lead storage battery. The determination step includes a charging current integration step for calculating the integrated value of the charging current of the lead storage battery, a discharge current integration step for calculating the integrated value of the discharge current of the lead storage battery, and a recovery carried out last time. Measurement of the charging current of the lead storage battery when the ratio of the integrated value of the charging current after the completion of charging and the integrated value of the discharge current after the completion of the recovery charging performed last time reaches a predetermined value. The value may be a measured value of the recovery charge end-stage current, and may include a determination processing step of determining the deterioration state of the lead storage battery based on the measured value and the corresponding relationship data.

[10] In the above diagnostic method, the determination step estimates a function indicating a change of the charging current in the constant voltage charging period with respect to time, based on the elapsed time in the constant voltage charging period and the measured value of the charging current. The function estimation step to be performed, the first parameter calculated based on the function estimated by the function estimation step, and the determination processing step for determining the deterioration state of the lead storage battery based on the correspondence data are included. It may be.

2. 2. Specific Examples of Embodiments Hereinafter, specific examples of embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals will be given to the components common to each embodiment, and repeated description will be omitted. In addition, it should be noted that the drawings are schematic, and the relationship between the dimensions of each element, the ratio of each element, and the like may differ from the reality. Even between drawings, there may be parts where the relationship and ratio of dimensions are different from each other.

<< Outline of Deterioration Diagnosis Method for Lead-Acid Battery According to the Present Invention >>
First, the outline of the deterioration diagnosis method of the lead storage battery according to the present invention will be described.
The inventors of the present application have described the charging current just before the end of the recovery charging of the lead-acid battery, in other words, the charging current at the end of the constant voltage (CV) charging period in the recovery charging (hereinafter, also referred to as "recovery charging final current"). It was found that there is a correlation between the value of and the number of charge / discharge cycles of the lead storage battery, and it is possible to determine the degree of deterioration of the lead storage battery corresponding to the charge / discharge cycle of the lead storage battery from the recovery charge end-stage current.

FIG. 1 is a diagram showing the relationship between the number of charge / discharge cycles of a lead-acid battery and the final recovery charge current.
FIG. 1 shows the case where the completion condition of the recovery charge is "when the charging current becomes 0.5 A or less after switching to CV charging" or "when 12 hours have passed after switching to CV charging". In addition, the recovery charge end-stage current just before the completion of recovery charge is measured, and the correspondence relationship with the number of charge / discharge cycles is graphed. In the figure, the vertical axis represents the recovery charge end current of the lead-acid battery, and the horizontal axis represents the number of charge / discharge cycles of the lead-acid battery.
As shown in the figure, the recovery charge terminal current tends to increase with the number of charge / discharge cycles of the lead-acid battery.

FIG. 2 is a diagram showing the relationship between the number of charge / discharge cycles of the lead storage battery and the capacity of the storage battery.
In the figure, the vertical axis represents the storage battery capacity of the lead-acid battery, and the horizontal axis represents the number of charge / discharge cycles of the lead-acid battery.
As shown in the figure, the storage battery capacity tends to decrease as the number of charge / discharge cycles of the lead storage battery increases.

A graph showing the relationship between the recovery charge end-stage current of the lead-acid battery and the storage battery capacity based on FIGS. 1 and 2 is as shown in FIG. In FIG. 3, the vertical axis represents the recovery charge terminal current of the lead-acid battery, and the horizontal axis represents the storage battery capacity of the lead-acid battery.
As can be understood from FIG. 3, there is a correlation between the end-of-recovery charge current and the storage battery capacity of the lead-acid battery, and the storage battery capacity of the lead-acid battery tends to decrease as the end-of-recovery charge current increases.

Therefore, by measuring the recovery charge terminal current during the recovery charge of the lead storage battery and referring to the correspondence relationship between the recovery charge terminal current and the storage battery capacity of the lead storage battery obtained in advance based on the measured value, the measurement can be performed. It is possible to determine the storage battery capacity of the lead storage battery at that time, that is, the deterioration state of the lead storage battery.

Further, the increase in the recovery charge terminal current means that the time until the recovery charge is completed, that is, the time until the charge current drops to a predetermined current value after switching to the CV charge becomes longer.

FIG. 4 is a diagram showing the relationship between the number of charge / discharge cycles of the lead-acid battery and the time until the charging current drops to a predetermined current value. In FIG. 4, the vertical axis represents the number of charge / discharge cycles of the lead-acid battery, and the horizontal axis represents the period until the charging current drops from the first threshold value Is1 to the second threshold value Is2 (<Ith1) during the CV charging period in the recovery charging. (Hereinafter, also referred to as “charging current convergence time”).
As shown in FIG. 4, as the number of charge / discharge cycles of the lead-acid battery increases, the charge current convergence time tends to increase.

Therefore, the charging current convergence time is measured during the recovery charging of the lead-acid battery, and based on the measured value, the charge current convergence time and the number of charge / discharge cycles (or the number of charge / discharge cycles) of the lead-acid battery obtained in advance correspond to each other. By referring to the correspondence with the storage battery capacity), it is possible to determine the deterioration state of the lead storage battery at that time.
Hereinafter, specific embodiments of the above-described lead storage battery deterioration diagnosis method will be described.

<< Embodiment 1 >>
FIG. 5 is a diagram showing a configuration of a power storage system according to the first embodiment of the present invention.
The power storage system 100 shown in the figure is, for example, a power storage system including a lead storage battery for cycle use. For example, the power storage system 100 supplies power to the load 8 from the power supply unit 3 (commercial power supply) during normal operation, and supplies power to the load 8 from the lead storage battery 7 for power supply backup when a power failure occurs.

The power supply unit 3 is a functional unit that supplies electric power to the power storage system 100 and the load 8. The power supply unit 3 is, for example, a commercial power source. In addition to the commercial power source, the power supply unit 3 may have a power generation facility that generates electric power based on renewable energy such as photovoltaic power generation (PV: Photovoltaics).

The power storage system 100 includes a storage battery 7, a PCS (Power Conditioning System) 4, a current sensor 5, a voltage sensor 6, a monitoring device 1, and a control device 2.

The storage battery 7 is a lead storage battery configured to be able to charge and discharge electric power. The storage battery 7 is a power storage module configured by connecting a single cell or a plurality of cells in series. Hereinafter, the storage battery 7 is also referred to as a “lead storage battery 7”.

The PCS 4 is controlled by a control device 2 described later, converts electric power between the power supply unit 3, the lead-acid battery 7, and the load 8 to each other, and is used between the power supply unit 3, the lead-acid battery 7, and the load 8. It is a power conversion unit that controls the transfer of power. For example, the PCS 4 converts the alternating current power (AC) from the power supply unit 3 into direct current power (DC) and supplies it to the lead storage battery 7. The PCS4 includes, for example, a DC / DC converter, an AC / DC converter (AC / DC), a switch circuit, and the like.

The current sensor 5 and the voltage sensor 6 are functional units for measuring physical quantities indicating the state of the lead storage battery 7. The current sensor 5 measures the charge current and the discharge current of the lead-acid battery 7. The voltage sensor 6 measures the output voltage (storage battery voltage) of the lead storage battery 7.

The monitoring device 1 and the control device 2 control the overall operation of the power storage system 100 as a whole.

The monitoring device 1 is a data processing device that sequentially acquires physical quantities measured by the current sensor 5 and the voltage sensor 6 and monitors the state of the lead-acid battery 7 based on the physical quantities. The monitoring device 1 is, for example, a BMU (Battery Management Unit).

The control device 2 is a device that controls each component of the power storage system 100. Specifically, the control device 2 controls the charge / discharge of the lead storage battery 7 by driving the PCS 4. For example, the control device 2 executes recovery charging of the lead-acid battery 7 by a constant current-constant voltage charging (CCCV) method or a multi-stage charging method in response to an instruction from the monitoring device 1. The control device 2 is, for example, an EMS (Energy Management System).

The monitoring device 1 and the control device 2 include, for example, a processor such as a CPU (Central Processing Unit), a storage device such as a RAM (Random Access Memory) or a ROM (Read Only Memory), and a peripheral circuit such as an I / F circuit. The monitoring device 1 and the control device 2 described above are realized by the processor executing various operations according to the program stored in the storage device to control peripheral circuits.

The monitoring device 1 has a diagnostic function for diagnosing the deteriorated state of the lead storage battery 7 as one of the monitoring functions of the lead storage battery 7.
FIG. 6 is a diagram showing a configuration of the monitoring device 1 according to the first embodiment.
As shown in the figure, the monitoring device 1 has a communication unit 11, a measurement control unit 12, a storage unit 13, and a determination unit 14 as functional units for realizing the above-mentioned diagnostic function.

The communication unit 11 is a functional unit that transmits / receives data to / from the control device 2.

The measurement control unit 12 is a functional unit (measurement result acquisition unit) that controls the current sensor 5 and the voltage sensor 6 and acquires the measurement result of the physical quantity measured by the current sensor 5 and the voltage sensor 6. For example, the measurement control unit 12 periodically acquires current and voltage measurement values from the current sensor 5 and the voltage sensor 6. Further, the measurement control unit 12 acquires current and voltage measurement values from the current sensor 5 and the voltage sensor 6 in response to an instruction from the determination unit 14. The current value and the voltage value acquired by the measurement control unit 12 are stored in the storage unit 13. For example, the measured values of the charge current and the discharge current of the lead-acid battery 7 and the measured values of the storage battery voltage of the lead-acid battery 7 are stored in the storage unit 13 as the measurement result 131.

The storage unit 13 is a functional unit that stores various data necessary for realizing the diagnostic function. For example, the storage unit 13 stores the measurement result 131 acquired by the measurement control unit 12. Further, the storage unit 13 stores the correspondence data 132, which will be described later, in advance.

The determination unit 14 is a functional unit for determining the deteriorated state of the lead storage battery 7.
The determination unit 14 determines the deterioration state of the lead-acid battery 7 based on the measured value of the charging current in the constant voltage charging period of the recovery charge of the lead-acid battery 7 and the correspondence data 132 stored in the storage unit 13.

The correspondence data 132 is data showing the correspondence between the first parameter relating to the charging current in the constant voltage charging period of the recovery charging of the lead storage battery 7 and the second parameter indicating the degree of deterioration of the lead storage battery 7.

Here, the first parameter is the recovery charge end-stage current described above, and the second parameter is the storage battery capacity of the lead-acid battery 7.
For example, as shown in FIG. 3 above, the correlation between the recovery charge terminal current of the lead-acid battery 7 and the storage battery capacity is obtained in advance by an experiment or the like, and the data showing the correlation is stored as the correspondence data 132. Remember in 13.

Further, the correspondence data 132 may be plural instead of one. For example, as shown in FIG. 1 above, the correlation between the recovery charge terminal current of the lead-acid battery 7 and the charge / discharge cycle is obtained in advance by experiments or the like, and the data showing the correlation is used as the first correspondence data. Further, as shown in FIG. 2 above, the correlation between the charge / discharge cycle of the lead-acid battery 7 and the storage battery capacity is obtained in advance by experiments or the like, and the data showing the correlation is stored as the second correspondence data. It may be stored in the part 13.

The correspondence data 132 described above may be any data indicating the relationship between the first parameter and the second parameter, and the data structure and the like thereof are not particularly limited. For example, the correspondence data 132 may be a function indicating the relationship between the first parameter and the second parameter, or may be data in a table format such as a lookup table.

Specifically, the determination unit 14 includes a timekeeping unit 140 and a determination processing unit 141.
The time measuring unit 140 measures the time from when the charging current drops below a predetermined threshold value to the elapse of a predetermined time t1 during the constant voltage charging period of the recovery charging of the lead storage battery 7. For example, the timekeeping unit 140 is a timer counter, and when it detects that the charging current has dropped below a predetermined threshold value during the constant voltage charging period of the recovery charging of the lead storage battery 7, it starts counting and a predetermined count value is set in advance. When the set value corresponding to the time t1 is matched, the notification signal is output.

The determination processing unit 141 sets the measured value of the charging current when a predetermined time elapses after the charging current drops below the predetermined threshold value in the constant voltage charging period of the recovery charging of the lead-acid battery 7 as the measured value of the recovery charging final current. The deterioration state of the lead-acid battery 7 is determined based on the measured value and the correspondence data 132. For example, the determination processing unit 141 uses the measured value of the charging current when the notification signal is output from the time measuring unit 140 as the measured value of the recovery charging final current.

Next, a diagnostic method for diagnosing the deteriorated state of the lead-acid battery 7 by the monitoring device 1 according to the first embodiment will be specifically described.
FIG. 7 is a flowchart showing a flow of a diagnostic method for diagnosing a deteriorated state of the lead storage battery according to the first embodiment.

FIG. 8 is a timing chart showing the charging current and the storage battery voltage of the lead-acid battery 7 during recovery charging. In FIG. 8, the vertical axis represents current and voltage, and the horizontal axis represents time. Further, reference numeral 300 represents the charging current of the lead storage battery 7, and reference numeral 400 represents the storage battery voltage of the lead storage battery 7. As an example, FIG. 8 shows temporal changes in the charging current and the storage battery voltage when recovery charging is performed by the constant current-constant voltage charging (CCCV) method.

As shown in FIG. 8, in the CCCV type recovery charging, CC charging is first started at a constant current value I1. After that, when the storage battery voltage reaches a predetermined voltage Vc, CC charging is stopped, CV charging is performed at a constant voltage Vc, and the lead storage battery 7 is restored to a fully charged state.

As shown in FIG. 7, first, when the constant voltage charging for recovery charging is started, in the constant voltage charging period (CV charging period), is the charging current I lower than the predetermined threshold value Is? It is determined whether or not (step S11). In step S11, when the charging current I becomes lower than the predetermined threshold value Is, the monitoring device 1 starts timing by the timing unit 140 (step S12).

Next, the monitoring device 1 determines whether or not a predetermined time t1 has elapsed since the charging current I fell below the predetermined threshold value Is (step S13).

In step S13, when the predetermined time t1 has elapsed, the monitoring device 1 sets the measured value of the charging current at that time as the measured value of the recovery charging final current (step S14). For example, in FIG. 8, the time measuring unit 140 outputs a signal when the predetermined time t1 elapses, and the measurement control unit 12 converts the measured value Icv of the charging current acquired from the current sensor 5 in response to the signal to the recovery charging final current. It is a measured value.

Next, the monitoring device 1 determines the deterioration state of the lead storage battery based on the measured value of the charging current acquired in step S14 and the correspondence data 132 (step S15). Specifically, the determination processing unit 141 measures the recovery charge terminal current acquired in step S14 based on the correspondence data 132 indicating the relationship between the recovery charge terminal current and the storage battery capacity stored in the storage unit 13. Calculate the storage battery capacity corresponding to the value. The determination processing unit 141 determines the deterioration state of the lead storage battery based on the calculated storage battery capacity.

As described above, the monitoring device 1 according to the first embodiment includes the measured value of the charging current in the constant voltage charging period of the recovery charging of the lead storage battery, and the first parameter and lead regarding the charging current in the constant voltage charging period, which have been obtained in advance. The deterioration state of the lead-acid battery is determined based on the correspondence data showing the correspondence with the second parameter indicating the degree of deterioration of the storage battery.

According to this, it is possible to grasp the degree of deterioration of the lead-acid battery based on the recovery charge terminal current that correlates with the storage battery capacity of the lead-acid battery. Therefore, sensors for measuring the internal resistance of the lead-acid battery can be used. There is no need to install a new one.

Further, according to this, since it is possible to grasp the degree of deterioration of the lead storage battery at the time of recovery charging which is carried out regularly, no special charge / discharge is required to determine the deterioration as in the capacity test. As a result, it is not necessary to stop the operation of the power storage system, and the time for determining the deterioration of the lead storage battery can be significantly shortened.

Further, according to this, since the recovery charge terminal current is measured by the combination of the charging current and the time, it can be applied to a power storage system that performs recovery charging by a multi-stage charging method such as a stationary storage battery.

Therefore, according to the monitoring device 1 according to the first embodiment, it is possible to more easily diagnose the deteriorated state of the lead storage battery regardless of the recovery charging method.

Further, in the monitoring device 1 according to the first embodiment, the measured value of the charging current when a predetermined time elapses after the charging current drops below the predetermined threshold value in the constant voltage charging period is set as the measured value of the recovery charging end stage current. The deterioration state of the lead storage battery is determined based on the measured value and the correspondence data 132. According to this, since the final recovery charging current, that is, the charging current just before the end of recovery charging can be appropriately measured, it is possible to determine the degree of deterioration of the lead storage battery with higher accuracy.

<< Embodiment 2 >>
In the diagnostic method according to the first embodiment, the deterioration state of the lead storage battery is determined based on the recovery charge terminal current, but in the diagnostic method according to the second embodiment, the deterioration state of the lead storage battery is determined based on the charging current convergence time. Determine the state. The power storage system according to the second embodiment is different from the power storage system according to the first embodiment in the configuration of the monitoring device, and is the same as the power storage system according to the first embodiment in other respects.

FIG. 9 is a diagram showing a configuration of a monitoring device according to the second embodiment.
In the second embodiment, the first parameter of the correspondence data 132A is the charging current convergence time from when the charging current reaches the first threshold value Is1 to when it reaches the second threshold value Is2 (<Ith1) during the constant voltage charging period. (T2), the second parameter of the correspondence data 132A is the storage battery capacity of the lead storage battery 7.

For example, as shown in FIG. 4 above, the correlation between the charging current convergence time t2 of the lead-acid battery 7 and the number of charge / discharge cycles (or the storage battery capacity corresponding to the number of charge / discharge cycles) is obtained in advance by experiments or the like. Then, the data showing the correlation is stored in the storage unit 13 as the correspondence relationship data 132A.

The determination unit 14A of the monitoring device 1A shown in FIG. 9 includes a timing unit 140A and a determination processing unit 141A.

The time measuring unit 140A measures the charging current convergence time from when the charging current reaches the first threshold value Is1 to when it reaches the second threshold value Is2 (<Ith1) during the constant voltage charging period. The time measuring unit 140A is, for example, a counter, and starts the counting operation when the measured value of the charging current reaches the first threshold value Is1 during the constant voltage charging period, and the measured value of the charging current becomes the second threshold value Is2. Occasionally, the counting operation is stopped, and the counting value at that time is stored as the measured value of the charging current convergence time.

The determination processing unit 141A determines the deterioration state of the lead storage battery 7 based on the time measurement value by the time measuring unit 140A and the correspondence data 132A. For example, the determination processing unit 141A calculates the storage battery capacity corresponding to the measured value of the charging current convergence time by the time measuring unit 140A based on the correspondence data 132A indicating the relationship between the charging current convergence time and the storage battery capacity. Determine the deterioration state of the lead-acid battery.

Next, a diagnostic method for diagnosing the deteriorated state of the lead storage battery 7 by the monitoring device 1A according to the second embodiment will be specifically described.
FIG. 10 is a flowchart showing a flow of a diagnostic method for diagnosing a deteriorated state of the lead storage battery according to the second embodiment.

FIG. 11 is a timing chart showing the charging current and the storage battery voltage of the lead-acid battery 7 during recovery charging. In FIG. 11, the vertical axis represents current and voltage, and the horizontal axis represents time. Further, reference numeral 301 represents the charging current of the lead storage battery 7, and reference numeral 401 represents the storage battery voltage of the lead storage battery 7. As an example, FIG. 11 shows temporal changes in the charging current and the storage battery voltage when recovery charging is performed by the constant current-constant voltage charging (CCCV) method.

As shown in FIG. 10, the monitoring device 1A determines whether or not the charging current I has reached a predetermined first threshold value Is1 in the constant voltage charging period (CV charging period) of the recovery charging (step S21). In step S21, when the charging current I reaches the first threshold value Is1, the monitoring device 1A starts timing by the timing unit 140A (step S22).

Next, the monitoring device 1A determines whether or not the charging current I has reached the second threshold value Is2, which is lower than the first threshold value Is1 (step S23). In step S23, when the charging current I has not reached the second threshold value Is2, the time counting by the time measuring unit 140A is continued.
On the other hand, when the charging current I reaches the second threshold value Is2 in step S23, as shown in FIG. 11, the monitoring device 1A ends the time counting by the time measuring unit 140A, and the measurement time t2 at that time is set as the charging current. It is a measured value of the convergence time (step S24).

Next, the monitoring device 1A determines the deterioration state of the lead storage battery based on the measured value of the charging current convergence time acquired in step S24 and the correspondence data 132A stored in the storage unit 13 (step S25). For example, the storage battery capacity corresponding to the measured value of the charging current convergence time acquired in step S24 by the determination processing unit 141A of the monitoring device 1A based on the correspondence data 132 indicating the relationship between the charging current convergence time t2 and the storage battery capacity. Is calculated. The determination processing unit 141A determines the deterioration state of the lead storage battery based on the calculated storage battery capacity.

As described above, according to the monitoring device 1A according to the second embodiment, it is possible to more easily diagnose the deteriorated state of the lead storage battery regardless of the recovery charging method, as in the monitoring device 1 according to the first embodiment. It becomes.

Further, the monitoring device 1A according to the second embodiment measures the charging current as the measured value of the time from when the charging current reaches the first threshold value Is1 to when it reaches the second threshold value Is2 (<Ith1) in the constant voltage charging period. The deterioration state of the lead storage battery is determined based on the measured value of the convergence time t2 and the measured value and the correspondence data 132A. According to this, the charging current convergence time, that is, the temporal change of the charging current just before the end of recovery charging can be appropriately measured, so that the degree of deterioration of the lead storage battery can be determined with higher accuracy. Become.

<< Embodiment 3 >>
The power storage system according to the third embodiment is different from the power storage system according to the first embodiment in terms of a method for determining the recovery charge terminal current, and is the same as the power storage system according to the first embodiment in other respects.

FIG. 12 is a diagram showing a configuration of a monitoring device according to the third embodiment.
The determination unit 14B of the monitoring device 1B shown in FIG. 12 includes a charge current integration unit 142, a discharge current integration unit 143, and a determination processing unit 141B.

The charging current integrating unit 142 is a functional unit that calculates an integrated value of the charging current of the lead storage battery 7. The discharge current integrating unit 143 is a functional unit that calculates an integrated value of the discharge current of the lead-acid battery 7. The charge current integration unit 142 and the discharge current integration unit 143 start integrating the charge current and the discharge current at the timing when the recovery charge is completed.

The determination processing unit 141B sets the measured value of the charging current of the storage battery when the ratio of the integrated value of the charging current and the integrated value of the discharging current becomes a predetermined value as the measured value of the recovery charging end current, and corresponds to the measured value. The deterioration state of the lead storage battery 7 is determined based on the relational data 132.

Specifically, the determination processing unit 141B includes the integrated value of the charging current calculated by the charging current integrating unit 142 after the completion of the previously executed recovery charging and the discharge current integrating unit after the completion of the previously executed recovery charging. The ratio with the integrated value of the discharge current calculated by 143 is calculated. For example, the determination processing unit 141B calculates the ratio [%] of the integrated value of the charging current to the integrated value of the discharge current. Next, the determination processing unit 141B compares the calculated ratio with the ratio reference value 134.

Here, the ratio reference value 134 is a reference value for determining the end of the constant voltage charging period in recovery charging. Generally, the recovery charge is overcharged so as to be 100% or more (for example, 104%) with respect to the discharge capacity. Therefore, the ratio reference value 134 is preferably set to a value exceeding 100%, for example, a value in the range of 101% to 104%.
The ratio reference value 134 is stored in the storage unit 13 in advance, for example.

The determination processing unit 141B uses the measured value of the charging current of the lead-acid battery 7 when the calculated ratio reaches the ratio reference value 134 as the measured value of the recovery charging end-stage current. Then, the determination processing unit 141B calculates the storage battery capacity corresponding to the acquired measured value of the recovery charge terminal current based on the correspondence data 132 indicating the relationship between the recovery charge terminal current and the storage battery capacity, thereby causing the lead storage battery. Judge the deterioration state of.

Next, a diagnostic method for diagnosing the deteriorated state of the lead storage battery 7 by the monitoring device 1B according to the third embodiment will be specifically described.
FIG. 13 is a flowchart showing a flow of a diagnostic method for diagnosing a deteriorated state of the lead storage battery according to the third embodiment.

FIG. 14 is a timing chart showing the charge current and discharge current of the lead-acid battery 7 during recovery charging. In FIG. 14, the vertical axis represents current and the horizontal axis represents time. Further, reference numeral 302 represents a charging current of the lead storage battery 7, and reference numeral 303 represents a discharging current of the lead storage battery 7.

First, the monitoring device 1B starts integrating the charging current and the discharging current of the lead storage battery 7 at the timing when the recovery charging is completed (step S31). For example, in FIG. 14, at the time t31 when the recovery charging is completed, the monitoring device 1B starts integrating the charging current of the lead-acid battery 7 by the charging current integrating unit 142, and discharges the lead-acid battery 7 by the discharging current integrating unit 143. Start integrating current.

Next, the monitoring device 1B calculates the ratio of the integrated value of the charging current by the charging current integrating unit 142 and the integrated value of the discharge current by the discharge current integrating unit 143 by the determination processing unit 141B (step S32). Specifically, the ratio of the integrated value of the charging current to the integrated value of the discharge current is calculated.

Next, the monitoring device 1B determines whether or not the ratio calculated in step S32 has reached the ratio reference value 134 by the determination processing unit 141B (step S33). In step S33, if the ratio calculated in step S32 does not reach the ratio reference value 134, the integration of the charge current and the discharge current is continued.

On the other hand, when the ratio calculated in step S32 reaches the ratio reference value 134, the monitoring device 1B acquires the measured value of the charging current at that time as the measured value of the recovery charging final current (step S34). For example, at time t32 in FIG. 14, when the ratio of the integrated value of the charging current to the integrated value of the discharge current matches the ratio reference value 134, the monitoring device 1B measures the charging current measured at time t32 by the measurement control unit 12. Let the measured value be the measured value of the recovery charge terminal current.

Next, the monitoring device 1B determines the deterioration state of the lead storage battery based on the measured value of the recovery charge terminal current acquired in step S34 and the correspondence data 132 (step S35). Specifically, the determination processing unit 141B measures the recovery charge terminal current acquired in step S34 based on the correspondence data 132 indicating the relationship between the recovery charge terminal current and the storage battery capacity stored in the storage unit 13. Calculate the storage battery capacity corresponding to the value. The determination processing unit 141B determines the deterioration state of the lead storage battery based on the calculated storage battery capacity.

As described above, according to the monitoring device 1B according to the third embodiment, it is possible to more easily diagnose the deteriorated state of the lead storage battery regardless of the recovery charging method, as in the monitoring device 1 according to the first embodiment. It becomes.

Further, the monitoring device 1B according to the third embodiment starts integrating the charging current and the discharging current after the recovery charging carried out last time is completed, and the ratio of the integrated value of the charging current and the integrated value of the discharge current is predetermined. The deterioration state of the lead-acid battery 7 is determined by using the measured value of the charging current of the storage battery when the value is reached as the measured value of the recovery end-stage current. According to this, as in the first embodiment, the charging current just before the end of the recovery charging can be appropriately measured, so that the degree of deterioration of the lead storage battery can be determined with higher accuracy.

<< Embodiment 4 >>
The power storage system according to the fourth embodiment is different from the power storage system according to the first embodiment in that the degree of deterioration of the lead storage battery is determined based on an approximate function of the logarithmic curve of the charging current during the constant voltage charging period of recovery charging. However, in other respects, it is the same as the power storage system according to the first embodiment.

FIG. 15 is a diagram showing the characteristics of the charging current in recovery charging.
In the figure, the vertical axis represents the charging current and the horizontal axis represents the time. Further, reference numeral 303 represents the charging current of the lead storage battery 7. As an example, FIG. 15 shows temporal changes in the charging current and the storage battery voltage when recovery charging is performed by the constant current-constant voltage charging (CCCV) method.

FIG. 16 is a diagram showing an example of a semi-logarithmic graph showing a function representing a change in charging current with time during a constant voltage charging period of recovery charging.
As shown in FIG. 16, the function represented by the equation (1) has characteristics such as reference numerals 501 to 503 when the charging current is expressed in a semi-logarithm. Reference numeral 501 represents a time change of the charging current of the lead-acid battery 7 having the number of charge / discharge cycles of C1, and reference numeral 502 represents a time change of the charging current of the lead-acid battery 7 having the number of charge / discharge cycles of C2 (> C1). Reference numeral 503 represents a time change of the charging current of the lead-acid battery 7 having the number of charge / discharge cycles of C3 (> C2).

In this way, the time change of the charging current of the lead-acid battery during the constant voltage charging period of recovery charging can be approximated to a straight line when displayed in one logarithm. Therefore, the change of the charging current with respect to time in the constant voltage charging period can be expressed by the following equation (1).

In the formula (1), I is the charging current of the lead-acid battery 7, and t is the time. Further, A is a constant. Further, in the equation (1), B is a time constant based on the internal resistance of the lead-acid battery 7 and the capacity of the lead-acid battery 7. Here, the capacity is a value peculiar to the lead storage battery 7 and is a constant value. On the other hand, the internal resistance increases according to the number of charge / discharge cycles (deterioration of the lead storage battery 7). Therefore, the time constant B is a parameter that correlates with the degree of deterioration of the lead storage battery.
Further, in the equation (1), I0 is a constant and corresponds to the recovery charge terminal current. That is, the constant I0 is a parameter that correlates with the degree of deterioration of the lead storage battery.

In this way, the change of the charging current with respect to time in the constant voltage charging period can be approximated by the above equation (1), and the value (constant IO) of the recovery charging end current or the gradient of the waveform depends on the number of charge / discharge cycles. (Time constant B) is different.
Therefore, in the monitoring device according to the fourth embodiment, the charging current is measured at regular intervals after the constant voltage charging is started, and the constant IO or the constant IO in the approximate expression (equation (1)) of the exponential function calculated from the measured value is used. The degree of deterioration of the storage battery is determined from the time constant B.

FIG. 17 is a diagram showing a configuration of the monitoring device 1C according to the fourth embodiment.
The determination unit 14C of the monitoring device 1C shown in FIG. 17 includes a function estimation unit 144 and a determination processing unit 141C.

The function estimation unit 144 estimates a function indicating a change in the charging current with respect to time in the constant voltage charging period based on the elapsed time in the constant voltage charging period of the recovery charging of the lead-acid battery 7 and the measured value of the charging current. Is. Specifically, the function estimation unit 144 uses the above-mentioned approximate expression (equation (1)) of the exponential function from the measured value of the charging current acquired by the measurement control unit 12 at regular time intervals after the start of constant voltage charging. presume. As a method for obtaining the approximate expression (equation (1)), the Levenberg-Marquardt method or the like of the sequential operation algorithm may be used.

The approximate expression (equation (1)) estimated by the function estimation unit 144 is stored in the storage unit 13 as the function data 135.

The determination processing unit 141C determines the deterioration state of the lead storage battery 7 based on the first parameter calculated from the function estimated by the function estimation unit 144 and the correspondence data 132C.

Here, the first parameter of the correspondence data 132C according to the fourth embodiment is the constant IO or the time constant B in the approximate expression (Equation (1)), and the second parameter of the correspondence data 132C is the lead storage battery 7. Battery capacity.

For example, as shown in FIG. 3 above, the correlation between the recovery charge end-stage current (constant IO) of the lead-acid battery 7 and the storage battery capacity is obtained in advance by experiments or the like, and the data showing the correlation is obtained as the correspondence data. It is stored in the storage unit 13 as 132C. Alternatively, as shown in FIG. 18, the correlation between the time constant B and the storage battery capacity in the approximate formula (formula (1)) of the lead storage battery 7 is obtained in advance by experiments or the like, and the data showing the correlation is obtained as a correspondence relationship. The data 132C is stored in the storage unit 13.

Next, a diagnostic method for diagnosing the deteriorated state of the lead storage battery 7 by the monitoring device 1C according to the fourth embodiment will be specifically described.
FIG. 19 is a flowchart showing a flow of a diagnostic method for diagnosing a deteriorated state of the lead storage battery according to the fourth embodiment.

First, the monitoring device 1C starts measuring the charging current when the constant voltage charging is started in the recovery charging (step S41). For example, the monitoring device 1B acquires the measured value of the charging current from the current sensor 5 at predetermined time intervals by the measurement control unit 12.

Next, the monitoring device 1C calculates an approximate expression representing a temporal change in the charging current based on the measured value of the charging current acquired during the constant voltage charging period (step S42). For example, the function estimation unit 144 of the monitoring device 1C calculates an approximate expression represented by the above equation (1) based on the measured values of the plurality of charging currents acquired by the measurement control unit 12, and stores it as the function data 135. It is stored in the part 13.

Next, the determination processing unit 141C of the monitoring device 1C acquires the first parameter in the approximate expression (formula (1)) calculated in step S43 (step S43). For example, the determination processing unit 141C acquires the constant IO or the time constant B from the function data 135 stored in the storage unit 13.

Next, the determination processing unit 141C of the monitoring device 1C determines the deterioration state of the lead storage battery 7 based on the first parameter acquired in step S44 and the correspondence data 132C (step S44).
For example, the determination processing unit 141C uses the constant IO of the approximate expression (Equation (1)) acquired in step S43 as the measured value of the recovery charge terminal current, and the correspondence data 132C showing the relationship between the recovery charge terminal current and the storage battery capacity. Based on, the storage battery capacity corresponding to the measured value of the recovery charge terminal current is calculated. Alternatively, the determination processing unit 141C has a storage battery corresponding to the value of the time constant B in the approximate expression (formula (1)) acquired in step S43 based on the correspondence data 132C indicating the relationship between the time constant B and the storage battery capacity. Calculate the capacity. Then, the determination processing unit 141B determines the deterioration state of the lead storage battery based on the calculated storage battery capacity.

As described above, according to the monitoring device 1C according to the fourth embodiment, it is possible to more easily diagnose the deteriorated state of the lead storage battery regardless of the recovery charging method, as in the monitoring device 1 according to the first embodiment. It becomes.

Further, the monitoring device 1C according to the fourth embodiment estimates a function (Equation (1)) based on the elapsed time in the constant voltage charging period and the measured value of the charging current, and the constant IO or the time constant B of the function. The degree of deterioration of the lead storage battery 7 is determined based on the above. According to this, as in the first embodiment, the charging current just before the end of the recovery charging or the temporal change of the charging current can be appropriately measured, so that the degree of deterioration of the lead storage battery can be more accurately measured. It becomes possible to judge.

≪Expansion of embodiment≫
The inventions made by the present inventors have been specifically described above based on the embodiments, but it goes without saying that the present invention is not limited thereto and can be variously modified without departing from the gist thereof. No.

For example, the flowchart described above is an example for explaining the operation, and is not limited thereto. That is, the steps shown in each figure of the flowchart are specific examples, and are not limited to this flow. For example, the order of some processes may be changed, other processes may be inserted between each process, and some processes may be performed in parallel.

1,1A-1C ... Monitoring device (data processing device), 2 ... Control device, 3 ... Power supply unit (PCS), 5 ... Current sensor, 6 ... Voltage sensor, 7 ... Storage battery (lead storage battery), 8 ... Load, 11 ... Communication unit, 12 ... Measurement control unit, 12 ... Measurement value acquisition unit, 13 ... Storage unit, 14, 14A, 14B, 14C ... Judgment unit, 100 ... Power storage system, 131 ... Measurement result, 132, 132A, 132C ... Correspondence-related data, 134 ... Ratio reference value, 135 ... Function data, 140, 140A ... Measuring unit, 141, 141A, 141B, 141C ... Judgment processing unit, 142 ... Charging current integrating unit, 143 ... Discharging current integrating unit 144 ... Function estimation unit.

Claims (8)

A measurement value acquisition unit that acquires the measurement value of the charging current during the constant voltage charging period of recovery charging of the lead-acid battery,
A storage unit that stores correspondence data representing the correspondence between the first parameter relating to the charging current during the constant voltage charging period and the second parameter indicating the degree of deterioration of the lead storage battery.
And the measurement value obtained by the measurement value acquisition unit, on the basis of the stored the correspondence data in the storage unit, have a, a determination unit state of deterioration of the lead-acid battery,
The first parameter is a recovery charging end current indicating the charging current at the end of the constant voltage charging period.
The measured value acquisition unit acquires the charge current of the lead-acid battery and the discharge current of the lead-acid battery.
The determination unit
A charging current integrating unit that calculates the integrated value of the charging current of the lead-acid battery,
A discharge current integrating unit that calculates the integrated value of the discharge current of the lead-acid battery,
The lead-acid battery when the ratio of the integrated value of the charging current after the completion of the recovery charging performed last time and the integrated value of the discharge current after the completion of the recovery charging performed last time becomes a predetermined value. A data processing device including a determination processing unit that determines a deterioration state of the lead-acid battery based on the measured value of the charging current as the measured value of the recovery charging end-stage current and the measured value and the corresponding relationship data . In the data processing apparatus according to claim 1,
The first parameter is a recovery charging end current indicating the charging current at the end of the constant voltage charging period.
The determination unit uses the measured value of the charging current when a predetermined time elapses after the charging current drops below the threshold value in the constant voltage charging period as the measured value of the recovery charging end-stage current, and the measured value and the corresponding relationship data. A data processing device for determining a deteriorated state of the lead storage battery based on the above. In the data processing apparatus according to claim 1,
The first parameter is a charging current convergence time indicating the time from when the charging current reaches the first threshold value to when it reaches the second threshold value smaller than the first threshold value during the constant voltage charging period.
The determination unit
A time measuring unit that measures the time from when the charging current reaches the first threshold value to when it reaches the second threshold value during the constant voltage charging period.
A data processing device including a determination processing unit that determines a deterioration state of the lead storage battery based on the measured value of the time measured by the time measuring unit and the correspondence data. In the data processing apparatus according to claim 1,
The determination unit
A function estimation unit that estimates a function indicating a change in the charging current with respect to time in the constant voltage charging period based on the elapsed time in the constant voltage charging period and the measured value of the charging current.
Data including a determination processing unit for determining a deterioration state of the lead-acid battery based on the first parameter calculated based on a function estimated by the function estimation unit and the correspondence data. Processing equipment. In the data processing apparatus according to claim 4 ,
When the charging current of the lead-acid battery is I, the time is t, the time constant is B, the first constant is I0, and the second constant is A, the function is expressed by the following equation (1).
The first parameter is a recovery charging end current representing the charging current at the end of the constant voltage charging period.
The determination processing unit uses the first constant of the function estimated by the function estimation unit as the measured value of the recovery charge end-stage current, and based on the measured value and the corresponding relationship data, the deterioration state of the lead storage battery. A data processing device characterized by determining.

In the data processing apparatus according to claim 4 ,
When the charging current of the lead-acid battery is I, the time is t, the time constant is B, the first constant is I0, and the second constant is A, the function is expressed by the following equation (1).
The first parameter is the time constant.
The determination processing unit is a data processing device that determines a deterioration state of the lead storage battery based on the time constant of the function estimated by the function estimation unit and the correspondence data.

It is a method for determining the deterioration state of lead-acid batteries.
A measurement value acquisition step for acquiring a measurement value of the charging current during the constant voltage charging period of the recovery charge of the lead-acid battery, and a measurement value acquisition step.
Correspondence representing the correspondence relationship between the measured value acquired by the measured value acquisition step, the first parameter regarding the charging current in the constant voltage charging period stored in the storage unit, and the second parameter indicating the degree of deterioration of the lead storage battery. based on the relationship data, see containing and a determination step of determining the deterioration state of the lead-acid battery,
The first parameter is a recovery charging end current indicating the charging current at the end of the constant voltage charging period.
In the measurement value acquisition step, the charge current and the discharge current of the lead storage battery are acquired, and the measurement value acquisition step is performed.
The determination step is
A charging current integration step for calculating the integrated value of the charging current of the lead-acid battery, and
A discharge current integration step for calculating the integrated value of the discharge current of the lead-acid battery, and
The lead-acid battery when the ratio of the integrated value of the charging current after the completion of the recovery charging performed last time and the integrated value of the discharge current after the completion of the recovery charging performed last time becomes a predetermined value. A diagnostic method including a determination processing step of determining a deterioration state of the lead-acid battery based on the measured value of the charging current as the measured value of the recovery charging end-stage current and the measured value and the corresponding relationship data . It is a method for determining the deterioration state of lead-acid batteries.
A measurement value acquisition step for acquiring a measurement value of the charging current during the constant voltage charging period of the recovery charge of the lead-acid battery, and a measurement value acquisition step.
Correspondence representing the correspondence relationship between the measured value acquired by the measured value acquisition step, the first parameter regarding the charging current in the constant voltage charging period stored in the storage unit, and the second parameter indicating the degree of deterioration of the lead storage battery. Including a determination step of determining the deterioration state of the lead-acid battery based on the related data.
The determination step is
A function estimation step for estimating a function indicating a change in the charging current with respect to time in the constant voltage charging period based on the elapsed time in the constant voltage charging period and the measured value of the charging current.
The first parameter calculated based on the function estimated by the function estimation step and a determination processing step for determining the deterioration state of the lead storage battery based on the correspondence data are included.
When the charging current of the lead-acid battery is I, the time constant is B, the first constant is I0, and the second constant is A, the function is expressed by the following equation (1).
The first parameter is a recovery charging end current representing the charging current at the end of the constant voltage charging period.
In the determination processing step, the first constant of the function estimated by the function estimation step is used as the measured value of the recovery charge end-stage current, and the deterioration state of the lead storage battery is based on the measured value and the corresponding relationship data. A diagnostic method characterized by determining.

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