Battery degradation diagnostic system and method for diagnosing battery degradation using this battery degradation diagnostic system

Abstract

The objective is to provide a battery degradation diagnosis system that allows for easy updates of degradation diagnosis algorithms and other related components. [Solution] The battery degradation diagnosis system 10 is characterized by comprising: a measurement unit 12 that measures the voltage, current, and temperature of the battery 4 at the site where the battery 4 is used; a transmitting and receiving unit 14 that transmits the voltage, current, and temperature data measured by the measurement unit 12; and a degradation diagnosis server unit 16 that stores the voltage, current, and temperature data transmitted by the transmitting and receiving unit 14, obtains correction information and characteristic information necessary to diagnose the degradation of the battery 4 based on the voltage, current, and temperature data, and performs correction processing and calculation processing based on the DC resistance value to perform the diagnosis.

Description

Technical Field

[0001] The present invention relates to a storage battery deterioration diagnosis system and a method for diagnosing deterioration of a storage battery using the storage battery deterioration diagnosis system.

Background Art

[0002] In recent years, storage batteries have been used in various places. Storage batteries deteriorate when used for a long period of time while repeating charging and discharging. As a technique related to the present invention, for example, Patent Document 1 discloses that when a contact terminal is pressed into contact with a terminal of a storage battery to measure the battery voltage of the storage battery, the contact terminal is formed in a flat plate shape, both ends of the contact terminal are supported by support members with different pressing forces, and the contact terminal is displaced and pressed against the terminal of the storage battery to tilt the contact terminal, thereby causing the contact terminal to slide sideways, and a method for measuring the battery voltage of the storage battery is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of Invention

Problems to be Solved by the Invention

[0004] In order to perform deterioration diagnosis of a storage battery, a device for measuring the battery voltage and the like of the storage battery to perform the deterioration diagnosis is prepared on site, and the battery voltage of the storage battery is measured for diagnosis. However, in this case, even if the deterioration diagnosis algorithm or the like is improved and updated, it takes time and cost to replace the device.

[0005] An object of the present invention is to provide a storage battery deterioration diagnosis system that can easily update a deterioration diagnosis algorithm and the like.

Means for Solving the Problems

[0006] The battery degradation diagnosis system according to the present invention is characterized by comprising: a measurement unit that measures the voltage, current, and temperature of a battery at the site where the battery is used; a transmission unit that transmits the voltage, current, and temperature data measured by the measurement unit; and a degradation diagnosis server unit that stores the voltage, current, and temperature data transmitted by the transmission unit, obtains correction information and characteristic information necessary for performing a degradation diagnosis of the battery based on the voltage, current, and temperature data, performs a correction process based on the DC resistance value to estimate the battery's capacity retention rate.

[0007] Furthermore, in the battery degradation diagnosis system according to the present invention, it is preferable that the degradation diagnosis server unit performs a degradation diagnosis of the battery based on the accumulated voltage, current, and temperature data.

[0008] Furthermore, in the battery degradation diagnosis system according to the present invention, it is preferable that the degradation diagnosis server unit predicts the degradation of the battery based on the accumulated degradation diagnosis results of the battery.

[0009] Furthermore, in the battery degradation diagnosis system according to the present invention, it is preferable that the degradation diagnosis server unit learns information regarding the degradation prediction of the battery and updates the degradation prediction algorithm.

[0010] Furthermore, in the battery degradation diagnostic system according to the present invention, it is preferable that the measurement unit performs measurements at multiple points when measuring the voltage, current, and temperature of the battery.

[0011] The present invention relates to a method for diagnosing the degradation of a storage battery, and is a method for diagnosing the degradation of a storage battery using a storage battery degradation diagnosis system comprising: a measuring unit that measures the voltage, current, and temperature of the storage battery at the site where the storage battery is used; a transmitting unit that transmits the voltage, current, and temperature data measured by the measuring unit; and a degradation diagnosis server unit that stores the voltage, current, and temperature data transmitted by the transmitting unit, obtains correction information and characteristic information necessary for performing a degradation diagnosis of the storage battery based on the voltage, current, and temperature data, performs a correction process based on the DC resistance value to estimate the capacity retention rate of the storage battery, and is characterized by comprising: a first step of measuring the voltage, current, and temperature of the storage battery using the measuring unit; a second step of transmitting the voltage, current, and temperature data obtained in the first step to the degradation diagnosis server unit using the transmitting unit; and a third step of performing a degradation diagnosis of the storage battery using the degradation diagnosis server unit. [Effects of the Invention]

[0012] According to the present invention, algorithms for deterioration diagnosis and the like can be easily updated. [Brief explanation of the drawing]

[0013] [Figure 1] This figure shows a battery degradation diagnosis system according to an embodiment of the present invention. [Figure 2] In the battery degradation diagnosis system according to an embodiment of the present invention, this is measurement data used to obtain correction information and characteristic information for diagnosing battery degradation. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the following, the same reference numerals will be used for similar elements in all drawings, and redundant explanations will be omitted. In addition, in the descriptions within the text, reference numerals previously mentioned will be used as necessary.

[0015] Figure 1 is a diagram showing a battery degradation diagnosis system 10 according to an embodiment of the present invention. Figure 2 is measurement data used in the battery degradation diagnosis system 10 to obtain correction information and characteristic information for performing degradation diagnosis of the battery 4. Figure 2(a) is a diagram showing an example of the change in the DC resistance value of the battery 4 at battery temperature, Figure 2(b) is a diagram showing an example of the change in the DC resistance value of the battery 4 at battery voltage, and Figure 2(c) is a diagram showing an example of the relationship between the capacity retention rate (SOH (State of Health)) of the battery 4 and the DC resistance value.

[0016] The battery degradation diagnosis system 10 is a system for diagnosing the degradation state of the battery 4. The battery degradation diagnosis system 10 comprises a measurement unit 12, a transmitting / receiving unit 14, a degradation diagnosis server unit 16 connected to the transmitting / receiving unit 14 via a network 2, a battery jig 18, and a code reader 20.

[0017] The battery 4 has a mechanism that internally holds electrical energy injected from the outside in the form of electric current in the form of a change in the state of chemical substances, so-called Gibbs energy. The internal potential of the battery 4 can be expressed in terms of Gibbs energy levels, and the energy associated with the potential difference defined by the fundamental level difference between the negative and positive electrodes, which are the battery components, and the abundance ratio of the working medium, is equivalent to the injected electrical energy. A lithium-ion secondary battery is an example of a battery 4.

[0018] The external shape of the battery 4 is a rectangular prism. A code for identifying the model number and individual identification information (serial number) of the battery 4 is displayed on the side of the battery 4. In the example shown in Figure 1, a barcode, which is a one-dimensional code, is displayed, but other codes such as a QR code (registered trademark), which is a two-dimensional code, may also be used.

[0019] The battery jig 18 has a fitting portion for fitting the storage battery 4, and is a jig for measuring the voltage, current and temperature of the storage battery 4 in a state where the storage battery 4 is fitted. It is preferable that the battery jig 18 is prepared as a jig adapted to the shape of each model number of the storage battery 4. Note that this does not apply to cases where measurement is performed in a state of being incorporated in another device (such as a charger) instead of measurement by an independent battery diagnostic device.

[0020] Since the battery jig 18 is prepared as a jig adapted to the shape of each model number of the storage battery 4, the user can set the storage battery 4 at an accurate measurement position only by fitting the storage battery 4 into the battery jig 18 without particular awareness, so that measurement for performing highly accurate diagnosis with good workability can be performed.

[0021] The code reader 20 is a barcode reader for optically detecting a barcode and analyzing the pattern of bars and spaces to convert it into a specific character. The code reader 20 has a predetermined light source and an optical sensor, and also has a mechanism for scanning a barcode. Since the output of the optical sensor is a weak analog signal, it is amplified and digitized (binarized) by a certain reference threshold value. A digital signal in which a space with high reflectance is set to "0" and a bar with low reflectance is set to "1" is converted and recorded in a memory. Then, the pattern is decoded and data is output through various interfaces. Here, although the code reader 20 is described as a barcode reader, it may be, for example, a QR code reader or the like.

[0022] The measurement unit 12 has a function of measuring the voltage, current, and temperature of the storage battery 4 at a site where the storage battery 4 is used. More specifically, the measurement unit 12 performs a short-time charging operation of the storage battery 4 from a measurement terminal connected to the terminal of the storage battery 4 fitted to the battery jig 18, and measures the voltage change, current change, temperature and the like of the storage battery 4 at that time. When measuring the voltage, current and temperature of the storage battery 4, the measurement unit 12 can also perform measurement at a plurality of points instead of a single point. Thereby, depending on the state of the storage battery 4, the diagnostic accuracy can be improved by multi-point measurement (waveform observation) of voltage / current.

[0023] The transceiver unit 14 has a function of transmitting data such as voltage, current, and temperature measured by the measurement unit 12. Specifically, the transceiver unit 14 transmits data such as the voltage, current, and temperature of the storage battery 4 fitted to the battery jig 18 to the deterioration diagnosis server unit 16. Note that when the model number of the storage battery 4 is read by the code reader 20, the model number of the storage battery 4 is also transmitted to the deterioration diagnosis server unit 16. In addition, if an individual identification number (serial number) is also read in addition to the model number, the individual identification number is also transmitted to the deterioration diagnosis server unit 16.

[0024] The transceiver unit 14 has a function of receiving data transmitted from the deterioration diagnosis server unit 16, which is the result of the deterioration diagnosis of the storage battery 4 performed by the deterioration diagnosis server unit 16. Further, the transceiver unit 14 has a function of receiving data transmitted from the deterioration diagnosis server unit 16, which is the result of the later-described deterioration prediction of the storage battery 4 performed by the deterioration diagnosis server unit 16.

[0025] The transceiver unit 14 has a function of receiving data transmitted from the deterioration diagnosis server unit 16, which is the result of the later-described estimation of the disposal time of the storage battery 4 performed by the deterioration diagnosis server unit 16. Further, the transceiver unit 14 has a function of receiving data related to other diagnosis results transmitted from the deterioration diagnosis server unit 16 as well.

[0026] The data received by the transceiver unit 14 (for example, the result of the deterioration diagnosis of the storage battery 4, the result of the deterioration prediction of the storage battery 4, the estimation result of the disposal time of the storage battery 4) and the like can be transmitted to a display device (not shown) for display.

[0027] The deterioration diagnosis server unit 16 has a function of receiving the voltage, current, and temperature data transmitted by the transceiver unit 14, storing the data in a storage unit (not shown), and performing deterioration diagnosis of the storage battery 4 based on the voltage, current, and temperature data. Further, the deterioration diagnosis server unit 16 has a function of transmitting the result of the deterioration diagnosis of the storage battery 4 to the transceiver unit 14.

[0028] Furthermore, the degradation diagnosis server unit 16 has the function of predicting the degradation of the battery 4 based on the voltage, current, and temperature data of the battery 4 stored in the memory unit. The degradation diagnosis server unit 16 also has the function of transmitting the results of the battery 4 degradation prediction to the transmission / reception unit 14.

[0029] Furthermore, the degradation diagnosis server unit 16 has a function to estimate the disposal time of the storage battery 4 based on the degradation prediction of the storage battery 4. The degradation diagnosis server unit 16 also has a function to transmit the result of the estimated disposal time of the storage battery 4 to the transmission / reception unit 14.

[0030] Furthermore, the degradation diagnosis server unit 16 has the function of learning information related to the degradation prediction of the battery 4 and updating the degradation prediction algorithm. Here, the learning of information related to the degradation prediction of the battery 4 is described as machine learning, but for example, it may be learned using deep learning. In addition, the degradation diagnosis server unit 16 has the function of learning information related to the degradation diagnosis of the battery 4 and updating the degradation diagnosis algorithm.

[0031] <Preparation for the deterioration diagnosis service> As a preliminary step for the degradation diagnosis server unit 16 to perform a degradation diagnosis of the storage battery 4, it is possible to perform a simple diagnosis based on pre-prepared standard correction information and characteristic information for the storage battery 4. However, this explanation will describe a high-precision diagnosis based on correction information and characteristic information for each model number of the storage battery 4.

[0032] When performing a high-precision diagnosis using characteristic data for each model number of the storage battery 4, a sample of the relevant model number is prepared in advance, and correction information and characteristic information such as voltage, current, and temperature of the storage battery 4 for degradation diagnosis are measured and created, and stored in the memory unit.

[0033] Here, the degradation diagnosis server unit 16 pre-measures data for each model number of the storage battery 4 under various conditions and stores it in the memory unit. First, let's explain Figure 2(a). The DC resistance value of the storage battery 4 changes significantly with battery temperature. This is mainly due to the electrochemical characteristics of the storage battery 4. The main factors are thought to be ion mobility, electrolyte viscosity, electrode reaction rate, and SEI coating on the negative electrode surface. Therefore, a method is used to correct for the effect of battery temperature by measuring the characteristics of the target storage battery 4 and converting those characteristics into data. Note that in Figure 2(a), in order to show examples of changes due to battery temperature, the data is limited to several batteries with different state of health (SOH) and a battery voltage of 3.7V, but in reality, measurements are taken under many more conditions.

[0034] Next, let's explain Figure 2(b). The DC resistance of the storage battery 4 also changes depending on the battery voltage. This is also mainly due to the electrochemical properties of the battery. The main factors include electrode reactions and electrolyte conductivity, and other factors include changes in the internal structure of the electrode material. For this reason, we take a method of measuring the characteristics of the target battery, digitizing those characteristics, and correcting for the effects of the battery voltage. Note that in Figure 2(b), in order to show examples of changes due to battery voltage, we have limited the display to data from several batteries with different states of health (SOH) and a battery temperature of 25°C, but in reality, measurements are taken under many more conditions.

[0035] Next, Figure 2(c) will be explained. The DC resistance value of the battery 4 is related to the state of health (SOH), and it is possible to estimate the SOH from the DC resistance value. However, this requires correction processing to reduce the effects of battery temperature and battery voltage. In this example, in order to show the relationship between the SOH and the DC resistance value, the data is limited to when the battery temperature is 25°C and the battery voltage is 3.7V, but in reality, measurements are taken under many more conditions. Here, as a means of determining the SOH of the battery 4, when investigating the amount of electricity that can be stored in the battery 4, charging is started from a completely discharged state and the total amount of electricity (in Ah or Coulombs) until full charge is measured, or after full charge, discharging is started and the total amount of electricity or total energy (in Wh) until complete discharge is measured, and the relationship between the DC resistance value and the measured SOH is plotted.

[0036] The battery characteristic data for battery 4 is a two-dimensional data structure using battery temperature and battery voltage as reference keys. The referenced coefficient A and constant B are then applied as correction information and characteristic information to the following calculation formula to estimate the state of health (SOH) of the battery. Capacitance retention ratio (SOH) = Coefficient A × F (DC resistance) + Constant B ... Equation (1) Here, the relationship data between the capacity retention rate (SOH) and DC resistance value at each battery temperature and voltage (actual battery measurements) is approximated by least squares approximation to the above relationship formula to obtain two correction information values, coefficient A and constant B, as well as characteristic information, which are then stored as a battery characteristic data table.

[0037] <Deterioration Diagnosis Service> At each site, a short-term charging operation of the battery 4 is performed, and characteristic information such as voltage changes, current changes, and temperature is measured by the measurement unit 12, and this data is transmitted by the transmission / reception unit 14. At this time, if the model number of the battery 4 is measured by the code reader 20, the model number of the battery 4 is also transmitted.

[0038] The degradation diagnosis server unit 16 performs a degradation diagnosis of the battery 4 using a degradation diagnosis algorithm based on the characteristic information of the battery 4 it receives. The results are stored in the storage unit of the degradation diagnosis server unit 16 and sent to the transmission / reception unit 14, the source of the characteristic information of the battery 4. If the battery 4 has model number information, it is also stored in the storage unit of the degradation diagnosis server unit 16 along with the model number. If there is an individual identification number (serial number) in addition to the model number, this is also stored.

[0039] Specifically, the degradation diagnosis of the storage battery 4 is performed by determining the state of health (SOH) of the storage battery 4. The DC resistance value of the storage battery is determined based on the battery and voltage transmitted from the transmitting / receiving unit 14. Furthermore, correction information for coefficient A and constant B, as well as characteristic information, are obtained from the above battery characteristic data table based on the voltage and temperature of the storage battery 4, and the state of health (SOH) of the storage battery 4 is estimated by applying these to equation (1). This has the advantage of allowing for a more accurate diagnosis by performing a correction process that reduces the influence of battery temperature and battery voltage compared to estimating the state of health (SOH) of the storage battery 4 based solely on the DC resistance value of the storage battery 4.

[0040] The degradation diagnosis server unit 16 performs a degradation diagnosis of the battery 4 as described above, which allows it to predict future degradation of the battery 4 and estimate when the battery 4 should be disposed of. This information is stored in the memory unit of the degradation diagnosis server unit 16 and can also be transmitted to the transmitting / receiving unit 14.

[0041] As described above, the transmitting / receiving unit 14 receives the results of the battery degradation diagnosis, the battery degradation prediction, and the estimated disposal date of the battery 4 transmitted from the degradation diagnosis server unit 16. This received data can be displayed on a display device accessible to the user. At this time, according to the user's wishes, for example, the results of the battery degradation diagnosis can be ranked and displayed in a way that distinguishes between ranks.

[0042] If there are problems with the degradation diagnosis of battery 4, additional sample batteries 4 will be prepared, as done in the preparation for the degradation diagnosis service, and correction information and characteristic information for degradation diagnosis will be updated, taking into consideration past measurement results stored in the memory of the degradation diagnosis server unit 16.

[0043] As described above, with the battery degradation diagnosis system 10, at sites where the battery 4 is used, only a measurement unit 12 is needed to measure the voltage, current, temperature, etc. of the battery 4. Since the degradation diagnosis algorithm is stored in the degradation diagnosis server unit 16, updating the degradation diagnosis server unit 16 enables degradation diagnosis with the latest information at all sites, which is a remarkable effect.

[0044] Furthermore, the battery degradation diagnosis system 10 has the advantage that the degradation diagnosis server unit 16 predicts the degradation of the battery 4 and estimates its disposal date, allowing the user to prepare their budget accordingly. [Explanation of Symbols]

[0045] 2 network, 4 storage batteries, 10 storage battery degradation diagnostic system, 12 measurement unit, 14 transmitting / receiving unit, 16 degradation diagnostic server unit, 18 battery jig, 20 code reader.

Claims

1. A measuring unit for measuring the voltage, current, and temperature of a storage battery at a site where the storage battery is used, A transmitting unit that transmits the voltage, current, and temperature data measured by the measuring unit, A degradation diagnosis server unit stores the voltage, current, and temperature data transmitted by the transmission unit, obtains correction information and characteristic information necessary for performing a degradation diagnosis of the storage battery based on the voltage, current, and temperature data, and performs correction processing and calculation processing based on the DC resistance value to estimate the capacity retention rate of the storage battery. A battery degradation diagnostic system characterized by having the following features.

2. In the battery degradation diagnosis system according to claim 1, The battery degradation diagnosis system is characterized in that the degradation diagnosis server unit performs a degradation diagnosis of the battery based on the accumulated voltage, current, and temperature data.

3. In the battery degradation diagnosis system according to claim 2, The battery degradation diagnosis system is characterized in that the degradation diagnosis server unit predicts the degradation of the battery based on the accumulated degradation diagnosis results of the battery.

4. In the battery degradation diagnosis system according to claim 2, The battery degradation diagnosis system is characterized in that the degradation diagnosis server unit learns information regarding the degradation prediction of the battery and updates the degradation prediction algorithm.

5. In the battery degradation diagnosis system according to claim 2, The battery degradation diagnosis system is characterized in that the degradation diagnosis server unit learns information related to the degradation diagnosis of the battery and updates the degradation diagnosis algorithm.

6. In the battery degradation diagnosis system according to claim 1, The battery degradation diagnostic system is characterized in that the measurement unit performs measurements at multiple points when measuring the voltage, current, and temperature of the battery.

7. A measuring unit for measuring the voltage, current, and temperature of a storage battery at a site where the storage battery is used, A transmitting unit that transmits the voltage, current, and temperature data measured by the measuring unit, A degradation diagnosis server unit stores the voltage, current, and temperature data transmitted by the transmission unit, obtains correction information and characteristic information necessary for performing a degradation diagnosis of the storage battery based on the voltage, current, and temperature data, performs a correction process based on the DC resistance value to estimate the capacity retention rate of the storage battery, A method for diagnosing battery degradation using a battery degradation diagnostic system equipped with, A first step involves measuring the voltage, current, and temperature of the storage battery using the measuring unit, A second step involves using the transmitting unit to transmit the voltage, current, and temperature data acquired in the first step to the degradation diagnosis server unit, A third step involves performing a degradation diagnosis of the storage battery using the degradation diagnosis server unit, A method for diagnosing the deterioration of a storage battery, characterized by comprising the following features.

Images