Battery degradation diagnostic system

Abstract

To provide a storage battery deterioration diagnosis system that is higher in reliability on a deterioration diagnosis of a storage battery than ever.SOLUTION: A storage battery deterioration diagnosis system comprises a temperature sensor 5 that measures an operation temperature of a storage battery 2, and a server device 10, in which a database 13 is provided that stores data associating SOH with the operation temperature of the storage battery and the number of recharging / discharging thereof, data associating the SOH with the operation temperature of the storage battery and a full-charging standby period thereof, and data associating the SOH with an impedance value of the storage battery, a server processing unit 11 is configured to: calculate an actually measured impedance value inside the storage battery 2 based on measured values received from a storage battery unit 1 upon diagnosing; calculate an estimated impedance value of the storage battery 2 using parameters associated with the SOH; and diagnose a deterioration state of the storage battery 2 from comparison of the actually measured impedance value with the estimated impedance value.SELECTED DRAWING: Figure 1

Description

【Technical Field】 【0001】 The present invention relates to a battery degradation diagnosis system for diagnosing the degradation state of a battery used for, for example, an emergency power source or power storage of surplus power. 【Background Art】 【0002】 Conventionally, for example, a battery used for an emergency power source or power storage of surplus power deteriorates, reducing the power that can be stored and making it impossible to fully exhibit its function. Therefore, when the degradation progresses to a certain extent, it needs to be replaced. Thus, as a degradation diagnosis system for diagnosing the degradation state of a battery, a system has been devised that supplies a measurement current (alternating current) to the battery to measure the impedance value and diagnoses the degradation state of the battery based on the measured impedance value. 【0003】 For example, in the degradation diagnosis system described in Patent Document 1, when supplying a measurement current to the battery, the frequency is changed to measure the impedance value for each frequency, and based on the frequency characteristic curve, an impedance value with an imaginary part of 0 is obtained, and the degradation state of the battery is determined based on this impedance value. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2007-333494 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 However, in the conventional degradation diagnosis system, since the degradation state of the battery was diagnosed based only on the measurement values obtained each time of measurement, there was a problem that the reliability of the degradation diagnosis was low. 【0006】 Therefore, the present invention has been made in view of the above problems, and aims to provide a battery degradation diagnosis system that is more reliable than conventional systems for diagnosing battery degradation. [Means for solving the problem] 【0007】 To achieve the above objective, the invention described in claim 1 of the present invention is a battery degradation diagnosis system having a current supply unit that supplies alternating current as a measurement current to a storage battery, a current measurement unit that measures the current flowing through the storage battery, a voltage measurement unit that measures the voltage of the storage battery, and a degradation diagnosis control unit that diagnoses the degradation state of the storage battery by calculating the internal impedance value of the storage battery from the supplied measurement current and the voltage at the time of supplying the measurement current, wherein the storage battery This is the average temperature from the start of operation to the present. A temperature measurement unit is provided to measure the operating temperature. Meanwhile, the number of charge and discharge cycles of the battery is measured, It is associated with State of Health (SOH), which is the percentage of the full charge capacity at the time of degradation, with the initial full charge capacity set to 100%. Ta Pa Glitter The relationship between the SOH and the number of charge / discharge cycles at a predetermined operating temperature, and the relationship between the SOH and the impedance value at a predetermined operating temperature. A storage unit is provided to store the impedance at the time of diagnosis, and the degradation diagnosis control unit diagnoses the degradation of the storage battery. The value is the measured impedance value inside the battery. as calculation In addition, using the operating temperature and the parameters Calculate the estimated impedance value and the aforementioned Measured impedance value and the above Estimated impedance value This method is characterized by diagnosing the degradation state of the storage battery by comparing it with the following. Furthermore, in order to achieve the above objective, the invention described in claim 2 of the present invention is a battery degradation diagnosis system comprising a current supply unit that supplies alternating current as a measurement current to a storage battery, a current measurement unit that measures the current flowing through the storage battery, a voltage measurement unit that measures the voltage of the storage battery, and a degradation diagnosis control unit that diagnoses the degradation state of the storage battery by calculating the internal impedance value of the storage battery from the supplied measurement current and the voltage at the time of supplying the measurement current, wherein a temperature measurement unit is provided that measures the operating temperature, which is the average temperature of the storage battery from the start of operation to the present, The standby period for fully charging the aforementioned battery is measured, It is associated with State of Health (SOH), which is the percentage of the full charge capacity at the time of degradation, with the initial full charge capacity set to 100%. The parameters include the relationship between the State of Health (SOH) and the fully charged standby period at a predetermined operating temperature, and the relationship between the SOH and the impedance value at a predetermined operating temperature. A memory unit is provided for storing the data, and the degradation diagnosis control unit, in diagnosing the degradation of the storage battery, calculates the impedance value at the time of diagnosis as the actual measured impedance value inside the storage battery, calculates an estimated impedance value using the operating temperature and the parameters, and diagnoses the degradation state of the storage battery by comparing the actual measured impedance value and the estimated impedance value. [Effects of the Invention] 【0008】 According to the present invention, the storage battery This is the average temperature from the start of operation to the present. A temperature measuring unit is provided to measure the operating temperature, The number of charge / discharge cycles of the storage battery (Claim 1), or the waiting period for the storage battery to be fully charged (Claim 2), is measured, It is associated with State of Health (SOH), which is the percentage of the full charge capacity at the time of degradation, with the initial full charge capacity set to 100%. Ta Pa Glitter The relationship between SOH at a predetermined operating temperature and the number of charge / discharge cycles (Claim 1) or the full charge standby period (Claim 2), and the relationship between SOH at a predetermined operating temperature and the impedance value. A memory unit is provided to store the impedance at the time of diagnosis, and the degradation diagnosis control unit diagnoses the degradation of the storage battery. The value is the measured impedance value inside the battery. as calculation In addition, using the operating temperature and parameters Calculate the estimated impedance value death, Measured impedance value and Estimated impedance value The degradation state of the storage battery is diagnosed by comparing it with the following. Therefore, the degradation diagnosis is performed using not only the measured values ​​obtained at the time of measurement, but also parameters associated with the operating temperature and SOH. Calculate the estimated impedance value and, Estimated impedance value By using this method to diagnose the degradation state of the storage battery, it is possible to create a storage battery degradation diagnosis system that is more reliable than conventional systems in terms of diagnosing storage battery degradation. [Brief explanation of the drawing] 【0009】 [Figure 1] This is a diagram illustrating an example of a battery degradation diagnosis system. [Figure 2] This graph shows the relationship between the State of Health (SOH) of a battery and the number of charge / discharge cycles at the first operating temperature. [Figure 3] This graph shows the relationship between the State of Health (SOH) of the battery and the impedance value of the battery at the first operating temperature. [Figure 4] This graph shows the relationship between the State of Health (SOH) and the number of charge / discharge cycles of a battery at the second operating temperature. [Figure 5] This graph shows the relationship between the State of Health (SOH) of the battery and the impedance value of the battery at the second operating temperature. [Figure 6] This graph shows the relationship between the State of Health (SOH) of a battery and the standby time for full charge at the first operating temperature. [Figure 7] This graph shows the relationship between the State of Health (SOH) of the battery and the impedance value of the battery at the first operating temperature. [Modes for carrying out the invention] 【0010】 Hereinafter, a battery degradation diagnosis system according to an embodiment of the present invention will be described in detail based on the drawings. 【0011】 FIG. 1 is a configuration diagram showing an example of the degradation diagnosis system 30. The degradation diagnosis system 30 includes a battery unit 1 including a battery 2, a server device 10 arranged separately from the battery unit 1, and a portable terminal 20 having an operation unit and a display unit carried by an operator or a user. Wireless communication is possible between the battery unit 1 and the server device 10, and between the server device 10 and the portable terminal 20, for example, by LTE communication or the like. 【0012】 The battery unit 1 includes a battery 2, a temperature sensor 5 for measuring the temperature of the battery 2, a current measurement unit 6 for measuring the current (operating current) of the battery 2, and a voltage measurement unit 7 for measuring the voltage of the battery 2. Further, the battery unit 1 is provided with a current supply unit 8 that supplies an alternating current as a measurement current to the battery 2 for the degradation diagnosis of the battery 2. Furthermore, the battery unit 1 is provided with a unit processing unit 3 that controls the acquisition of measurement data by the temperature sensor 5, the current measurement unit 6, and the voltage measurement unit 7, and a unit communication unit 4 for transmitting the measurement data, whether the battery 2 is in a charged state or a discharged state (that is, data related to the charge-discharge cycle), and the full-charge standby period of the battery 2 to the server device 10. 【0013】 The server device 10 includes a database 13 that stores the measurement data transmitted from the battery unit 1 and past data as described later, a server processing unit 11 and a determination unit 14 that diagnose the degradation state of the battery 2 using the received measurement data and test data as described later, a first server communication unit 12 for communicating with the battery unit 1, and a second server communication unit 15 for communicating with the portable terminal 20. 【0014】 Here, we will explain the control related to the degradation diagnosis of the storage battery 2 by the degradation diagnosis system 30. Figures 2 and 4 are graphs showing the relationship between the state of health (SOH) of the storage battery and the number of charge / discharge cycles at a predetermined operating temperature. Figures 3, 5, and 7 are graphs showing the relationship between the SOH of the storage battery and the impedance value of the storage battery at a predetermined operating temperature. Figure 6 is a graph showing the relationship between the SOH of the storage battery and the full charge standby period at a predetermined operating temperature. First, the type of battery 2 in the battery unit 1 to be subjected to degradation diagnosis is pre-configured in the server device 10. The database 13 of the server device 10 also stores test data from various types of batteries tested in battery units containing those batteries. This test data includes data relating the battery's degradation state (i.e., the percentage of the full charge capacity at the time of degradation relative to the initial full charge capacity, hereinafter referred to as SOH) to the operating temperature and the number of charge / discharge cycles (for example, data shown in Figures 2 and 4), data relating SOH to the operating temperature and the full charge standby period (for example, data shown in Figure 6), and data relating SOH to the battery's impedance value (for example, data shown in Figures 3, 5, and 7). The graphs shown in Figures 3, 5, and 7 can be obtained by plotting the impedance values ​​calculated while varying the frequency of the measured current for a rechargeable battery with a known SOH. 【0015】 The battery unit 1 measures the temperature sensor 5, current measurement unit 6, and voltage measurement unit 7 at predetermined measurement intervals (for example, every 10 minutes) from the start of operation of the battery 2, and transmits these measured values ​​as measurement data to the server device 10. The battery unit 1 also transmits a charging signal to the server device 10 when charging of the battery 2 begins, and a discharge signal to the server device 10 when discharging of the battery 2 begins. Furthermore, for a fully charged battery 2, the battery unit 1 measures the standby period in that state (i.e., the fully charged standby period), and transmits this measured value to the server device 10 as well. 【0016】 Furthermore, when the server device 10 receives the above measurement data from the battery unit 1, it associates these measurement data with each other and stores them as past data (stored as time-series data) in association with the time of reception. In addition, it calculates the number of charge and discharge cycles of the battery 2 based on the charge and discharge signals received from the battery unit 1, and associates this number of charge and discharge cycles with the above past data, as well as the full charge standby period, and stores it in association with the past data. 【0017】 When a worker or user operates the mobile terminal 20 and requests a degradation diagnosis of the battery 2 using the degradation diagnosis system 30, the server processing unit 11 sends a diagnostic test signal to the battery unit 1, causing the battery unit 1 to supply a measurement current to the battery 2 and measure the voltage of the battery 2 when the measurement current is supplied, and then sends these measured values ​​to the server device 10. The server processing unit 11 then calculates the actual impedance value (diagnostic data) inside the battery 2 based on the received measured values. 【0018】 Meanwhile, the server device 10 calculates an estimated impedance value (threshold data) of the battery 2 based on the test data stored in the database 13. In calculating this estimated impedance value, the server device 10 uses test data corresponding to the mode specified by the mobile terminal 20 for the degradation diagnosis. Specifically, if a degradation diagnosis based on the number of charge / discharge cycles is specified, the estimated impedance value is calculated using data relating SOH, operating temperature, and the number of charge / discharge cycles, and data relating SOH and the impedance value of the battery. Also, if a degradation diagnosis based on the full charge standby period is specified, the estimated impedance value is calculated using data relating SOH, operating temperature, and the full charge standby period, and data relating SOH and the impedance value of the battery. 【0019】 To explain in more detail, if a degradation diagnosis based on the number of charge / discharge cycles is specified, the type of battery 2 and the operating temperature of battery 2 (for example, the average temperature from the start of operation to the present) are referenced, and if the operating temperature is 25°C, the data shown in Figures 2 and 3 is read. If the number of charge / discharge cycles at the time of the degradation diagnosis is 1000, then the SOH is determined to be 74% from Figure 2, and the estimated impedance value is calculated from the graph corresponding to SOH 74% in Figure 3 (the graph shown by the dashed line). On the other hand, if the operating temperature is 45°C, the data shown in Figures 4 and 5 is read, and if the number of charge / discharge cycles at the time of the degradation diagnosis is 2000, then the SOH is determined to be 68% from Figure 4, and the estimated impedance value is calculated from the graph corresponding to SOH 68% in Figure 5 (the graph shown by the long dashed line). 【0020】 Furthermore, if a degradation diagnosis based on the full charge standby period is specified, the type of battery 2 and the operating temperature of battery 2 are referenced, and if the operating temperature is 25°C, the data shown in Figures 6 and 7 is read. Then, if the full charge standby period at the time of the degradation diagnosis was 95 days, the SOH is determined to be 93% from Figure 6, and the estimated impedance value is calculated from the graph corresponding to SOH 93% in Figure 7 (the graph shown by the dashed line). 【0021】 Then, the determination unit 14 performs a degradation diagnosis of the storage battery 2 by comparing the measured impedance value with the estimated impedance value. That is, for example, if it is determined that the measured impedance value is higher than the estimated impedance value, it is determined that the battery is "degraded," and if the measured impedance value is less than or equal to the estimated impedance value, it is determined that the battery is "not degraded." The diagnosis result related to the degradation diagnosis is then transmitted to the mobile terminal 20 and displayed on the display screen of the mobile terminal 20. 【0022】 According to the degradation diagnosis system 30 having the above configuration, a temperature sensor 5 is provided to measure the operating temperature of the storage battery 2, and a database 13 is provided in the server device 10 that stores data relating SOH to the operating temperature and charge / discharge cycle of the storage battery (parameters associated with SOH), data relating SOH to the operating temperature and full charge standby period of the storage battery (parameters associated with SOH), and data relating SOH to the impedance value of the storage battery (parameters associated with SOH). The server processing unit 11 calculates the actual impedance value inside the storage battery 2 (diagnostic data) based on the measurement values ​​received from the storage battery unit 1 during diagnosis, and calculates the estimated impedance value of the storage battery 2 (threshold data) using the parameters associated with SOH, and diagnoses the degradation state of the storage battery 2 by comparing the actual impedance value and the estimated impedance value. In this way, threshold data for degradation diagnosis is created using test data pre-stored in the database 13, not just the measured values ​​obtained at the time of measurement, and the degradation state of the battery 2 is diagnosed using this threshold data. As a result, the battery degradation diagnosis system 30 for the battery 2 can be made more reliable than conventional systems for diagnosing the degradation of the battery 2. 【0023】 Furthermore, the battery degradation diagnosis system according to the present invention is not limited in any way to the embodiments described above, and the overall configuration of the degradation diagnosis system, as well as the configuration related to battery degradation diagnosis, can be modified as needed. 【0024】 For example, in the above embodiment, battery degradation is diagnosed by comparing impedance values, but it is also possible to configure the system to calculate the State of Health (SOH) from the impedance value of the battery at the time of diagnosis and then diagnose battery degradation by comparing SOH values. Furthermore, in the above embodiment, the calculations related to the internal impedance value of the battery are performed by the server device, but the battery unit may be configured to perform the calculations related to the impedance value. Furthermore, it is also possible to eliminate the server device and configure the system so that all the functions of the server device in the embodiment are incorporated into the battery unit. 【0025】 Furthermore, in the above embodiment, the system is configured to allow the user to specify whether to perform a degradation diagnosis based on the number of charge / discharge cycles or on the standby period for full charge. However, there is no problem with a degradation diagnosis system that performs only one of these degradation diagnoses. Furthermore, if parameters associated with SOH are used, it is possible to use parameters other than those in the embodiment, and the operating temperature is not limited to that of the above embodiment. Furthermore, there is no problem in configuring the battery unit itself, rather than a portable terminal, to have an operating unit and display unit, where the degradation diagnosis is performed by operating the operating unit, and the results of the degradation diagnosis are displayed on the display unit. [Explanation of symbols] 【0026】 1. Battery unit, 2. Battery, 3. Unit processing unit (degradation diagnosis control unit), 5. Temperature sensor (temperature measurement unit), 6. Current measurement unit, 7. Voltage measurement unit, 8. Current supply unit, 10. Server device, 11. Server processing unit (degradation diagnosis control unit), 13. Database (storage unit), 14. Judgment unit (degradation diagnosis control unit), 20. Mobile terminal, 30. Degradation diagnosis system.

Claims

[Claim 1] A battery degradation diagnosis system comprising: a current supply unit that supplies alternating current as a measurement current to a storage battery; a current measurement unit that measures the current flowing through the storage battery; a voltage measurement unit that measures the voltage of the storage battery; and a degradation diagnosis control unit that diagnoses the degradation state of the storage battery by calculating the internal impedance value of the storage battery from the supplied measurement current and the voltage at the time the measurement current is supplied, A temperature measurement unit is provided to measure the operating temperature, which is the average temperature from the start of operation of the aforementioned storage battery to the present, The number of charge and discharge cycles of the aforementioned battery is measured, As a parameter associated with State of Health (SOH), which is the ratio of the full charge capacity at the time of degradation to the initial full charge capacity (set at 100%), The relationship between the SOH and the number of charge / discharge cycles at a predetermined operating temperature, Furthermore, a storage unit is provided for storing the relationship between the SOH and the impedance value at a predetermined operating temperature. The degradation diagnosis control unit, in diagnosing the degradation of the storage battery, calculates the impedance value at the time of diagnosis as the measured impedance value inside the storage battery, and calculates an estimated impedance value using the operating temperature and the parameters. A battery degradation diagnosis system characterized by diagnosing the degradation state of the battery by comparing the measured impedance value with the estimated impedance value. [Claim 2] A battery degradation diagnosis system comprising: a current supply unit that supplies alternating current to a battery as a measurement current; a current measurement unit that measures the current flowing through the battery; a voltage measurement unit that measures the voltage of the battery; and a degradation diagnosis control unit that diagnoses the degradation state of the battery by calculating the internal impedance value of the battery from the supplied measurement current and the voltage at the time of supplying the measurement current, A temperature measurement unit is provided to measure the operating temperature, which is the average temperature from the start of operation of the aforementioned storage battery to the present, The standby period for fully charging the aforementioned battery is measured, As a parameter associated with State of Health (SOH), which is the ratio of the full charge capacity at the time of degradation to the initial full charge capacity (set at 100%), The relationship between the SOH and the full charge standby period at a predetermined operating temperature, Furthermore, a storage unit is provided for storing the relationship between the SOH and the impedance value at a predetermined operating temperature. The degradation diagnosis control unit, in diagnosing the degradation of the storage battery, calculates the impedance value at the time of diagnosis as the measured impedance value inside the storage battery, and calculates an estimated impedance value using the operating temperature and the parameters. A battery degradation diagnosis system characterized by diagnosing the degradation state of the battery by comparing the measured impedance value with the estimated impedance value.

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