JP2014068434A - System and method for determining battery abnormality - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system and a method for determining battery abnormality capable of detecting an abnormal state based on the volume of a battery.SOLUTION: The system for determining battery abnormality includes: acquisition parts 12, 22 for acquiring information of the battery volume, a battery capacity maintenance factor, and average battery temperature; a storage part 32 for determining to which one of battery capacity maintenance factor sections divided by a predetermined range, and to which one of average battery temperature sections divided by a predetermined range, each of the information of the battery capacity maintenance factor and the average battery temperature obtained at the acquisition parts 12, 22 of multiple vehicles 10, 20 belongs, and storing information of the battery volume for each section to which the information belongs; a calculation part 33 for calculating, for each section to which the battery volume belongs, at least one of volume statistic values being an average value and a standard deviation of the battery volume stored at the storage part 32, in each section to which the battery volume belongs; and a determination part 24 for determining whether or not the battery volume of an own vehicle 20 is abnormal, on the basis of the volume statistic values at a section to which the battery capacity maintenance factor and the average battery temperature of the own vehicle 20 belong.

Description

  The present invention relates to a battery abnormality determination system and method.

  Conventionally, the battery information of the vehicle is transmitted to the center, the battery information is analyzed at the center to determine the battery state, and the battery information is subjected to various processes according to the battery deterioration degree which is one of the determined battery information. A management system has been proposed. In this system, a correction program corresponding to the degree of deterioration is distributed at the center, or a message prompting replacement is distributed to a battery that has exceeded its life (see Patent Document 1).

JP 2007-228657 A

  However, battery information transmitted conventionally does not take into account changes in the volume of the battery (electrode expansion or volume change due to gas generation). For this reason, an abnormal state based on the battery volume cannot be detected.

  The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a battery abnormality determination system and method capable of detecting an abnormal state based on the battery volume. It is in.

  In the battery abnormality determination system and method of the present invention, each of the information on the battery capacity maintenance rate and the average battery temperature acquired in the plurality of electric vehicles belongs to each of the battery capacity maintenance rate categories and each of the average battery temperature categories. Whether the battery volume of a specific electric vehicle is abnormal is determined from the volume statistic, and the volume statistic such as the average value or standard deviation is obtained for each categorization. to decide.

  According to the present invention, the battery volume tends to increase as the battery capacity retention rate decreases, and tends to increase as the average battery temperature increases. Such a tendency is normally generated when the battery is used, and the battery volume that falls within such a tendency is normal. On the other hand, for example, volume change due to electrode expansion or gas generation deviates from the above tendency range and the volume changes. Therefore, by storing a large amount of battery volume information for each category, battery volume information that captures the tendency that normally occurs is collected. Assuming that many battery volumes are normal, the volume statistic value for each category is a statistic value of the normal battery volume, and based on this, whether or not the battery volume of a specific electric vehicle is abnormal Can be judged. Therefore, it is possible to detect an abnormal state based on the battery volume.

It is a block diagram which shows the battery abnormality determination system which concerns on this embodiment. It is a figure which shows the memory content of the memory | storage part shown in FIG. It is a graph which shows the correlation with average cell temperature and capacity | capacitance maintenance factor, and cell volume increase amount. It is a flowchart which shows the battery abnormality determination method which concerns on this embodiment.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing a battery abnormality determination system according to the present embodiment. As shown in FIG. 1, the battery abnormality determination system 1 determines whether or not a battery 21 mounted on the host vehicle (specific vehicle) 20 is in an abnormal state. The side device 30 is configured.

  The plurality of vehicles 10 and 20 include batteries 11 and 21, acquisition units (acquisition means) 12 and 22, transmission / reception units 13 and 23, determination units (determination means) 14 and 24, and presentation units 15 and 25, respectively. The vehicle is driven by driving the motor with the electric power of the batteries 11 and 21, using the motor as a power source. The batteries 11 and 21 are secondary batteries such as lithium ion batteries that supply electric power to the motor and are charged during regeneration such as downhill.

  The acquisition units 12 and 22 acquire information on the battery volume, the battery capacity maintenance rate (the ratio of the current battery full charge capacity to the initial battery full charge capacity), and the average battery temperature. Specifically, the acquisition units 12 and 22 detect expansion of the batteries 11 and 21 based on signals from strain gauges, pressure sensors, and displacement sensors attached to the batteries 11 and 21 to detect the Get volume information. The acquisition units 12 and 22 calculate and acquire the battery capacity maintenance rate from the charging capacity at the time of charging, the battery voltage after full charging, and the like. Furthermore, the acquisition units 12 and 22 calculate and acquire the average battery temperature by integrating and averaging the signals of the temperature sensors provided in the batteries 11 and 21.

  The average battery temperature is preferably an average of temperatures from the start of use of the vehicles 10 and 20 (such as when the vehicle is delivered) to the present. This is because by acquiring the average temperature over a long period of time, the accuracy can be improved in the abnormality determination of the batteries 11 and 21 shown below.

  The transmission / reception units 13 and 23 communicate with the center side device 30 and transmit the information acquired by the acquisition units 12 and 22 to the center side device 30. The transmission / reception units 13 and 23 have a function of receiving information from the center-side device 30.

  In particular, in the present embodiment, the center side device 30 is configured to calculate a volume statistic value (or an appropriate volume range) for determining whether or not the batteries 11 and 21 of the vehicles 10 and 20 are abnormal. The units 13 and 23 are adapted to receive this information.

  The determination units 14 and 24 compare the information on the volume statistics (or appropriate volume range) received by the transmission / reception units 13 and 23 with the information on the battery volume acquired by the acquisition units 12 and 22, and It is determined whether 11 and 21 are in an abnormal state.

  The presentation units 15 and 25 include, for example, an image display unit and an audio output unit, and present various information to the user. In particular, in this embodiment, determination of battery abnormality determined by the determination units 14 and 24 is performed. It has a function of displaying the result and outputting sound. Thereby, the user can know whether or not the batteries 11 and 21 are in an abnormal state, and can determine whether or not the batteries 11 and 21 should be replaced.

  The center device 30 calculates a volume statistic value (or an appropriate volume range) for determining whether or not the batteries 11 and 21 are abnormal, and includes a transmission / reception unit 31 and a storage unit (storage unit) 32. And a calculation unit (calculation means) 33.

The transmission / reception unit 31 receives information from the transmission / reception units 13 and 23 of the plurality of vehicles 10 and 20 and transmits information to the transmission / reception units 13 and 23 of the plurality of vehicles 10 and 20. In particular, in this embodiment, the transmission / reception unit 31 receives information on the battery volume, the battery capacity maintenance rate, and the average battery temperature acquired by the acquisition units 12 and 22 of the plurality of vehicles 10 and 20.

  The storage unit 32 stores information received by the transmission / reception unit 31. FIG. 2 is a diagram showing the contents stored in the storage unit 32 shown in FIG. As shown in FIG. 2, the storage unit 32 includes each battery capacity maintenance rate section (each cell capacity section) divided in a predetermined range and each average battery temperature section (each cell temperature section) divided in a predetermined range. ) And battery volume information is stored.

  When the storage unit 32 receives information at the transmission / reception unit 31, the storage unit 32 determines which category the battery capacity maintenance rate of the received vehicles 10 and 20 belongs to, and which category the average battery temperature belongs to. The information of the battery volume is stored in the belonging category. And when information is received in the transmission / reception part 31 also about the other vehicles 10 and 20, the information of a battery volume is sequentially memorize | stored for every division to which it belongs.

  More specifically, assuming that the cell capacity is C1, the cell temperature is T1, and the information of the batteries 11 and 21 having the battery volume V1 is received, the storage unit 32 performs the classification of the category “C1T1”. Is stored as battery volume V1. Similarly, the storage unit 32 has a cell capacity of C1, a cell temperature of T1, and information on the batteries 11 and 21 having the battery volume V2 is received, the battery volume for the category “C1T1”. Store as V2. Further, the storage unit 32 has a cell capacity of C2, a cell temperature of T2, and information on the batteries 11 and 21 having the battery volume V3 is received, the battery volume V3 for the category “C2T2”. I remember.

  FIG. 3 is a graph showing the correlation between the average cell temperature and capacity retention rate and the cell volume increase. As shown in FIG. 3, it can be seen that the cell volume tends to increase as the average cell temperature increases. It can also be seen that the cell volume tends to increase as the capacity retention rate decreases. For this reason, in the present embodiment, the storage unit 32 stores battery volume information separately for each battery capacity maintenance rate section and each average battery temperature section.

  More specifically, the capacity retention rate of the normal batteries 11 and 21 decreases, and the volume increases as the average electric temperature increases. On the other hand, in the normal batteries 11 and 21, the capacity retention rate is high, and the volume increase is small when the average electric temperature is low. Thus, even if the same normal batteries 11 and 21 have different volumes depending on the capacity maintenance ratio and the average battery temperature, whether or not the batteries 11 and 21 are in an abnormal state simply from the volume alone. If it is determined, there is a high possibility that an erroneous determination result will be obtained. Therefore, in this embodiment, by storing the battery volume information separately for each battery capacity maintenance rate section and each average battery temperature section, the volume data of normal batteries 11 and 21 for each capacity maintenance ratio and temperature is stored. Accumulate and avoid making incorrect decisions.

  The calculator 33 calculates at least one volume statistical value of the average value and standard deviation of the battery volume stored for each category belonging to the storage unit 32 for each category to which the calculator 33 belongs. For example, since information on battery volumes V1 and V2 is stored in the category “C1T1”, the calculation unit 33 calculates at least one volume statistical value of the average value and the standard deviation for the battery volumes V1 and V2. .

  In more detail, the calculation unit 33 calculates an appropriate volume range of the battery volume from the volume statistics. Here, when the volume statistical value is a certain value α, the appropriate volume range is set to α ± β, for example.

  After the calculation unit 33 calculates the volume statistic value and the appropriate volume range as described above, the transmission / reception unit 31 transmits this information to the host vehicle 20 (specific vehicle). More specifically, when the cell capacity of the battery 21 of the host vehicle 20 is C1 to C2 and the cell temperature is T1 to T2, the transmission / reception unit 31 transmits the volume statistical value of the category “C1T1” and the information of the appropriate volume range. To do. Moreover, when the cell capacity or the cell temperature of the battery 21 of the host vehicle 20 is different, the transmission / reception unit 31 transmits the volume statistical value of the category and information on the appropriate volume range. That is, the center-side device 30 stores information from the plurality of vehicles 10 and 20, and for the host vehicle 20 that performs battery abnormality determination, the volume in the section to which the battery capacity maintenance rate and the average battery temperature of the host vehicle 20 belong. Statistics and appropriate volume range information will be transmitted.

  When the transmission / reception unit 23 receives information on the volume statistic and the appropriate volume range, the determination unit 24 determines the battery of the host vehicle 20 from the information on the battery volume of the host vehicle 20 and the received volume statistic and information on the proper volume range. It is determined whether 21 is abnormal.

  When the host vehicle 20 has received information on the proper volume range, the determination unit 24 determines that the battery 21 is normal when the battery volume of the host vehicle 20 is within the proper volume range, and is within the proper volume range. If it does not fall within the range, it is determined that the battery 21 is abnormal.

  Here, when an abnormality (volume change) due to electrode expansion or gas generation occurs in the battery 21, the battery volume greatly differs from the storage unit 32. Therefore, the determination unit 24 can determine the abnormality of the battery 21 from the volume statistic value stored in the storage unit 32 and information on the appropriate volume range.

  The storage unit 32 also stores battery volume information when an abnormality (volume change) due to electrode expansion or gas generation occurs, but most of the stored information is stored in the normal battery 11, Therefore, the calculation unit 33 performs the averaging process and the standard deviation process, so that the influence is reduced and the abnormality determination of the battery 21 can be performed without any trouble.

  Further, for example, in the transmission / reception units 13 and 23, a threshold value is provided for the battery volume information, and if the battery volume is too abnormal, the battery volume information may not be transmitted to the center side device 30 in the first place. Good. In addition, the threshold may be set based on a volume statistic received from the center side device 30 or an appropriate volume range.

  Next, a battery abnormality determination method according to this embodiment will be described. FIG. 4 is a flowchart showing a battery abnormality determination method according to this embodiment. As shown in FIG. 4, first, the acquisition units 12 and 22 measure the volume of all the cells of the batteries 11 and 21 mounted (S1).

  Next, the acquisition units 11 and 21 acquire information on the cell capacity (capacity maintenance rate) and the average battery temperature, and the transmission / reception units 13 and 23 calculate the volume of all cells, the cell capacity (capacity maintenance rate), and the average battery temperature. Information is transmitted to the center side apparatus 30 (S2).

  Thereafter, the center-side device 30 receives the information transmitted in step S2 and performs the storage and calculation processes described above, and the transmission / reception unit 23 of the host vehicle 20 receives information on the appropriate volume range (S3). Note that, in the process of step S3, the information on the volume statistic value may be received instead of the information on the appropriate volume range or together with the information on the appropriate volume range. Moreover, the information received in step S3 is information on the appropriate volume range in the section to which the host vehicle 20 belongs among the sections shown in FIG.

And the judgment part 24 of the own vehicle 20 judges whether the battery 21 of the own vehicle 20 is abnormal based on the information of the appropriate volume range received in step S3 (S4). At this time,
The determination unit 24 determines whether or not the battery 21 is abnormal based on whether or not there is a cell that deviates from the appropriate volume range.

  When it is determined that there is no cell deviating from the appropriate volume range (S4: NO), the determination unit 24 transmits a normal signal to the presentation unit 25 (S5). Then, the process shown in FIG. 4 ends. In addition, since it is a normal signal in step S5, it is not necessary to present it to the user. Therefore, it is not presented that the signal is normal. May be.

  On the other hand, when it is determined that there is a cell deviating from the appropriate volume range (S4: NO), the determination unit 24 transmits a failure signal and information on the defective cell to the presentation unit 25 (S6). Thereby, the presentation unit 25 presents information that the battery 21 is abnormal and information on the abnormal cell, and outputs an alarm (S7). Then, the process shown in FIG. 4 ends.

  Thus, according to the battery abnormality determination system 1 and the method according to the present embodiment, each of the information on the battery capacity maintenance rate and the average battery temperature acquired in the plurality of vehicles 10 and 20 is the battery capacity maintenance rate. It is determined whether it belongs to each category or each average battery temperature category, battery volume information is stored for each category, volume statistics such as average value and standard deviation are obtained for each category, and volume statistics It is determined whether the battery volume of a specific electric vehicle is abnormal. Here, the battery volume tends to increase as the battery capacity retention rate decreases, and tends to increase as the average battery temperature increases. Such a tendency is normally generated when the battery is used, and the battery volume that falls within such a tendency is normal. On the other hand, for example, volume change due to electrode expansion or gas generation deviates from the above tendency range and the volume changes. Therefore, by storing a large amount of battery volume information for each category, battery volume information that captures the tendency that normally occurs is collected. Assuming that many battery volumes are normal, the volume statistical value for each category is a normal battery volume statistical value. Based on this, it is determined whether the battery volume of the host vehicle 20 is abnormal. Judgment can be made. Therefore, it is possible to detect an abnormal state based on the battery volume.

  Moreover, in order to determine whether or not the battery volume of the host vehicle 20 is abnormal based on whether or not the appropriate volume range of the battery volume based on the volume statistics is within the appropriate volume range, An abnormality can be determined by a simple comparison process of whether or not there is, and an abnormality determination can be performed not by a large-scale device like the center side device 30 but by an in-vehicle device, and the abnormality determination is executed on the vehicle side. Can do.

  In addition, since the average temperature is an average of the temperatures from the start of use of the vehicles 10 and 20 to the present time, it is possible to consider the influence of the average temperature over a long period on the battery volume.

  As described above, the present invention has been described based on the embodiments, but the present invention is not limited to the above-described embodiments, and modifications may be made without departing from the spirit of the present invention. For example, in the present embodiment, the determination units 14 and 24 are provided in the respective vehicles 10 and 20, but are not limited thereto, and may be provided in the center-side device 30. Further, the calculation unit 33 is not limited to the center side device 30 and may be provided in each of the vehicles 10 and 20.

DESCRIPTION OF SYMBOLS 1 ... Battery abnormality determination system 10 ... Vehicle 11 ... Battery 12 ... Acquisition part (acquisition means)
13. Transmission / reception unit 14 ... Determination unit (determination means)
15 ... Presentation section 20 ... Own vehicle (specific electric vehicle)
21 ... Battery 22 ... Acquisition unit (acquisition means)
23: Transmission / reception unit 24 ... Determination unit (determination means)
25 ... Presentation unit 30 ... Center side device 31 ... Transmission / reception unit 32 ... Storage unit (storage means)
33... Calculation unit (calculation means)

Claims (4)

A battery abnormality determination system for determining whether a battery mounted on an electric vehicle is in an abnormal state,
An acquisition means for acquiring information on battery volume, battery capacity retention rate, and average battery temperature;
Each of the information on the battery capacity maintenance rate and the average battery temperature acquired by the acquisition means of a plurality of electric vehicles is divided into a predetermined range and each average battery temperature is divided into a predetermined range. A storage means for determining which of the sections belongs, and storing information on the battery volume for each of the sections;
Calculating means for calculating at least one volume statistical value of the average value and standard deviation of the battery volume stored for each of the classifications belonging to the storage means for each of the classifications;
Determination means for determining whether or not the battery volume of a specific electric vehicle is abnormal based on the volume statistics calculated by the calculation means in the category to which the battery capacity maintenance rate of the specific electric vehicle and the average battery temperature belong When,
A battery abnormality determination system comprising: The calculation means calculates an appropriate volume range of the battery volume based on the volume statistics,
The determination means determines whether or not the battery volume of the specific electric vehicle is abnormal based on whether or not the battery volume of the specific electric vehicle is within the appropriate volume range. The battery abnormality determination system described in 1. The battery abnormality determination system according to claim 1, wherein the average temperature is an average of temperatures from the start of use of the vehicle to the present time. A battery abnormality determination method for determining whether a battery mounted on an electric vehicle is in an abnormal state,
An obtaining step for obtaining information on battery volume, battery capacity retention rate, and average battery temperature;
Information on the battery volume, battery capacity maintenance rate, and average battery temperature acquired in the acquisition step of the plurality of electric vehicles is divided into battery capacity maintenance rate categories divided by a predetermined range, and averages divided by a predetermined range. A storage step of determining which of the battery temperature categories belongs, and storing information on the battery volume for each category to which the battery temperature categories belong;
A calculation step of calculating at least one volume statistical value of an average value and a standard deviation of the battery volume stored for each of the belonging categories in the storing step for each of the belonging categories;
A determination step of determining whether or not the battery volume of the specific electric vehicle is abnormal from the volume statistical value calculated in the calculation step in the category to which the battery capacity maintenance rate of the specific electric vehicle and the average battery temperature belong; ,
A battery abnormality determination method comprising:

Images