JP2012083317A - Power storage unit diagnostic system and diagnostic method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine whether a power storage unit is in a life state or in an abnormal state.SOLUTION: A diagnostic system for determining a deterioration state of multiple power storage units (12) constituting a storage device (10) includes a voltage sensor (21) for detecting a voltage of each power storage unit, a controller (22) for determining whether each power storage unit is in a deterioration state based on detection results of the voltage sensor and a memory (22a) for storing information on the deterioration state when the controller determines that a power storage unit is in a deterioration state. The controller determines whether the power storage unit is in an abnormal state or in a life state by using the number of times of determining a deterioration state among the information stored in the memory. For example, when the number of times of determining that the power storage unit is in a deterioration state is more than one within a predetermined period, the controller determines that the power storage unit is in an abnormal state, and when the number becomes more than one when exceeding the predetermined period, the controller determines that the power storage unit is in a life state.

Description

  The present invention relates to a diagnostic apparatus and a diagnostic method that can determine whether a deterioration state of a power storage unit is an abnormal state or a life state.

  Patent Document 1 describes a battery diagnosis device that diagnoses a deterioration state of a battery by distinguishing between deterioration due to normal use and deterioration due to an abnormal factor. That is, it is determined whether the battery has deteriorated normally or abnormally by considering the charge / discharge capacity of the battery indicating the deterioration degree of the battery and the use degree of the battery.

  Specifically, whether or not the battery has deteriorated normally based on the results of acquiring multiple data on the charge / discharge capacity and the usage of the battery and plotting these data on a two-dimensional map of the capacity and the usage It is determined whether it has deteriorated abnormally.

JP 2008-309796 A JP 2004-190604 A JP 2005-176461 A JP 2007-302058 A JP 2002-165371 A JP 2003-167653 A

  An object of the present invention is to provide a technique capable of easily determining whether a battery is in an abnormal state or a life state by a method different from the technique described in Patent Document 1.

  1st invention of this application is a diagnostic apparatus which discriminate | determines the deterioration state of the some electrical storage unit which comprises an electrical storage apparatus, Comprising: Based on the detection result of the voltage sensor which detects the voltage of each electrical storage unit, and each voltage sensor, A controller that determines whether or not the power storage unit is in a deteriorated state; and a memory that stores information on the deterioration state when the controller determines that the power storage unit is in a deteriorated state. Here, the controller can determine whether the power storage unit is in an abnormal state or a life state by using the number of times of determination of the deterioration state among the information stored in the memory. For example, when the number of times of determination that the power storage unit is in a deteriorated state is a plurality of times within a predetermined period, it is determined that the power storage unit is in an abnormal state, and the number of times is determined when the number of times of determination exceeds a predetermined period. When it is determined that the power storage unit is in a life state.

  Here, the deterioration state includes a life state and an abnormal state. The life state is a deteriorated state caused by secular change, and the abnormal state is a deteriorated state caused by an external factor different from the secular change. Further, as the power storage unit, a single battery (secondary battery) can be used, or a battery block composed of a plurality of single batteries can be used. In addition, an electric double layer capacitor can be used instead of the secondary battery.

  The controller can determine whether or not the time interval when determining the deterioration state for the first time and when determining the deterioration state for the second time exceeds a predetermined period. Here, when the time interval exceeds the predetermined period, it can be determined that the power storage unit is in a life state, and when the time interval does not exceed the predetermined period, it can be determined that the power storage unit is in an abnormal state.

  Further, the controller can determine whether or not the elapsed time until determining the deterioration state for the second time exceeds a predetermined period. Here, when the elapsed time exceeds the predetermined period, it can be determined that the power storage unit is in a life state, and when the elapsed time does not exceed the predetermined period, it can be determined that the power storage unit is in an abnormal state.

  When it is determined that the controller is in an abnormal state, the controller can set a flag indicating the abnormal state, and when it is determined that the controller is in the life state, the controller can set a flag indicating the life state. Thereby, the deterioration state (abnormal state or life state) of the power storage unit can be stored.

  The deterioration state can be determined when the temperature of the power storage unit is within a predetermined temperature range. When the temperature of the power storage unit is too high or too low, the deterioration state may not be accurately determined. Therefore, the deterioration state determination accuracy can be improved by determining the deterioration state in a state where the temperature of the power storage unit is within a predetermined temperature range. Specifically, a temperature sensor for detecting the temperature of the power storage device is provided, a fan for guiding temperature adjusting air to the power storage device is driven, and the temperature detected by the temperature sensor is within a predetermined temperature range. When it is within the range, the degradation state can be determined.

  In addition, when the electronic device is operated by supplying power from the power storage device, the deterioration state can be determined based on the voltage change of the power storage unit accompanying the driving of the electronic device. As the electronic device, for example, an air conditioner that is mounted on a vehicle and adjusts the temperature in the passenger compartment can be used. If the air conditioner is used, the deterioration state can be determined while adjusting the temperature of the power storage device. In addition, after driving an air conditioner and discharging an electrical storage unit, the deterioration state can be determined. When a nickel metal hydride battery is used as the power storage unit, the memory effect can be removed by discharging the power storage unit.

  2nd invention of this application is a diagnostic method which discriminate | determines the deterioration state of the some electrical storage unit which comprises an electrical storage apparatus, Comprising: Each electrical storage unit deteriorates based on the detection result of the voltage sensor which detects the voltage of each electrical storage unit A step of determining whether or not the battery is in a state, a step of storing information on the deterioration state in the memory when it is determined that the power storage unit is in a deterioration state, and a determination of the deterioration state among the information stored in the memory Determining whether the power storage unit is in an abnormal state or a life state using the number of times. For example, when the number of times of determination that the power storage unit is in a deteriorated state is a plurality of times within a predetermined period, it is determined that the power storage unit is in an abnormal state, and the number of times is determined when the number of times of determination exceeds a predetermined period. When it is determined that the power storage unit is in the life state, it can be determined.

  According to the present invention, it is possible to determine whether the power storage unit is in an abnormal state or a life state by referring to the number of times of determination when the deterioration state is determined.

In the vehicle of Example 1, it is a figure which shows the structure of the system containing an assembled battery. In Example 1, it is a flowchart which shows the process which discriminate | determines the abnormal state and lifetime state of a cell. It is table data obtained by the process of FIG. It is table data obtained by the process of FIG. It is a figure which shows the display information provided to a user. It is a figure which shows the display information provided to a store. It is a figure which shows the display information provided to a maker. 6 is a flowchart illustrating a process for determining an abnormal state and a life state of a unit cell in a modification of the first embodiment. In Example 2, it is a figure which shows the drive structure of an air conditioner and a fan. In Example 2, it is a flowchart explaining the process performed before discriminating the deterioration state of a cell. 10 is a flowchart for explaining processing performed before determining a deterioration state of a unit cell in a modification of the second embodiment. In Example 3, it is a flowchart which shows the process which discriminate | determines the deterioration state of a cell. It is a figure which shows the voltage behavior of the battery block accompanying the drive of an air conditioner, when an assembled battery exists in a normal state. It is a figure which shows the voltage behavior of the battery block accompanying the drive of an air conditioner, when the battery block of a degradation state has generate | occur | produced. It is a figure which shows the amount of voltage drops of a battery block accompanying the drive of an air conditioner. It is a figure which shows the voltage drop timing of a battery block accompanying the drive of an air conditioner. It is a figure which shows the change of the internal resistance of a battery block accompanying the drive of an air conditioner. It is a figure which shows the discharge pattern when measuring the internal resistance of a battery block.

  Examples of the present invention will be described below.

  A vehicle that is Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 shows a configuration of a system including an assembled battery in a vehicle. Examples of the vehicle of this embodiment include a hybrid vehicle and an electric vehicle. A hybrid vehicle is a vehicle that uses an internal combustion engine or a fuel cell in addition to an assembled battery as a power source for running the vehicle. An electric vehicle is a vehicle that uses only an assembled battery as a power source.

  The assembled battery (corresponding to a power storage device) 10 has a plurality of unit cells 11, and the plurality of unit cells 11 are electrically connected in series. The number of the single cells 11 can be appropriately set based on the required output of the assembled battery 10 or the like. As the cell 11, a secondary battery such as a nickel metal hydride battery or a lithium ion battery can be used. An electric double layer capacitor can be used instead of the secondary battery. In this embodiment, all the unit cells 11 are electrically connected in series, but a plurality of unit cells 11 electrically connected in parallel may be included.

  The voltage sensor 21 detects the voltage between the terminals of the battery block 12 and outputs the detection result to the controller 22. The battery block 12 includes a plurality of single cells 11 that are electrically connected in series, and the plurality of battery blocks 12 are electrically connected in series. The number of the single cells 11 constituting the battery block 12 can be set as appropriate. In the present embodiment, the voltage sensor 21 detects the voltage between the terminals of the battery block 12, but the voltage of the unit cell 11 can also be detected.

  The controller 22 controls charging / discharging of the assembled battery 10. The controller 22 has a memory 22a. In this embodiment, the memory 22 a is built in the controller 22, but a memory may be provided outside the controller 22.

  The assembled battery 10 is connected to a DC / DC converter 24 via system main relays 23a and 23b. On / off of the system main relays 23a and 23b is controlled by the controller 22. The DC / DC converter 24 boosts the output voltage of the assembled battery 10 and supplies it to the inverter 25. The DC / DC converter 24 steps down the voltage from the inverter 25 and supplies it to the assembled battery 10.

  The inverter 25 converts the DC power from the DC / DC converter 24 into AC power and supplies the AC power to a motor generator (three-phase AC motor) 26. The motor / generator 26 receives electric power from the inverter 25 and generates kinetic energy for running the vehicle. When the vehicle is decelerated or stopped, the motor / generator 26 converts the kinetic energy generated during braking of the vehicle into electrical energy and supplies it to the inverter 25. The inverter 25 converts AC power from the motor / generator 26 into DC power and supplies the DC power to the DC / DC converter 24.

  In the present embodiment, the controller 22 determines whether the unit cell 11 is in an abnormal state or a life state. This process will be described with reference to the flowchart shown in FIG. The process shown in FIG. 2 is executed by the controller 22.

  Here, the life state is a deterioration state that occurs due to aging of the unit cell 11, and the abnormal state is a deterioration state that occurs due to external factors. External factors include, for example, the environmental temperature and the state of charge, and the state of charge includes, for example, overcharge, overdischarge, and charge / discharge at a high rate. The abnormal state occurs before the occurrence time of the life state.

  2, the controller 22 monitors the battery block 12 (unit cell 11) based on the output of the voltage sensor 21. In the present embodiment, since the voltage sensor 21 detects the voltage between the terminals of the battery block 12, the controller 22 monitors the battery block 12. In step S102, the controller 22 determines whether or not there is a deteriorated unit cell 11 based on the monitoring result in step S101. If the deteriorated unit cell 11 exists, the process proceeds to step S103, and if the deteriorated unit cell 11 does not exist, the process returns to step S101.

  Based on the output of the voltage sensor 21, the controller 22 determines whether or not the cell 11 is in a deteriorated state. The controller 22 can monitor the voltages of the plurality of battery blocks 12 based on the outputs of the plurality of voltage sensors 21. When voltage variations occur in the plurality of battery blocks 12, it can be determined that one of the battery blocks 12 includes the deteriorated unit cell 11.

  For example, when the battery pack 10 is being discharged, if the voltage drop amount of a specific battery block 12 is larger than the voltage drop amount of another battery block 12, the unit cell 11 in a deteriorated state is placed in the specific battery block 12. It can be determined that it is included. Here, the difference between the voltage drop amount of a specific battery block 12 and the voltage drop amount of another battery block 12 is a criterion for determining whether or not there is a deteriorated unit cell 11. This criterion can be set as appropriate.

  In step S <b> 103, the controller 22 counts corresponding to the battery block 12 including the unit cell 11 in the deteriorated state among the count values (corresponding to information related to the deteriorated state) provided corresponding to each battery block 12. Increment the value. The count value is stored in the memory 22 a in a state associated with each battery block 12. In the initial state, the count value of each battery block 12 is set to “0”. When the count value is incremented, information regarding the date and time at this time is also stored in the memory 22a. Here, the date and time when the count value is “1” is T1, and the date and time when the count value is “2” is T2.

  FIG. 3 shows table data (an example) stored in the memory 22a. In the example shown in FIG. 3, the number of the battery block 12 (battery No) is used as the identification information of the battery block 12. The number of battery blocks 12 is the same as the number (n) of battery blocks 12. In the example illustrated in FIG. 3, the counter value corresponding to the battery block 12 of the battery No “k−1” is set to “1”, and the counter value corresponding to the battery block 12 of the battery No “k + 1” is set to “1”. Is set.

  In step S104, the controller 22 determines whether the count value is “1” or “2”. If the count value is “1”, the process returns to step S101. When it is determined again that the unit cell 11 is in the deteriorated state after returning to the process of step S101, the count value becomes “2”. When the count value is “2”, the process proceeds to step S105.

  In step S105, the controller 22 determines whether or not the interval between the date and time T1 and the date and time T2 is longer than the guaranteed period. The warranty period is a reference for determining whether the unit cell 11 is in the life state or the abnormal state, and can be set as appropriate based on the life period of the unit cell 11. The lifetime of the unit cell 11 can be determined based on past measured values when the unit cell 11 is used.

  The guarantee period can be stored in advance in the memory 22a. Further, it is possible to acquire information related to the warranty period by accessing a database provided outside the vehicle by wireless communication or wired communication. If the guarantee period is managed in the database, the guarantee period can be corrected based on the accumulated actual measurement value. By using the corrected warranty period, it is possible to improve the accuracy in determining the life state and the abnormal state.

  When the interval between the dates T1 and T2 is shorter than the guaranteed period, the process proceeds to step S106, and the controller 22 sets an abnormality flag. That is, the controller 22 determines that the battery block 12 having the count value “2” includes the unit cell 11 in an abnormal state. On the other hand, when the interval between the dates T1 and T2 is longer than the guaranteed period, the process proceeds to step S107, and the controller 22 sets a life flag. That is, the controller 22 determines that the battery cell 12 whose count value is “2” includes the unit cell 11 in the life state.

  FIG. 4 shows table data (an example) stored in the memory 22a. In the example shown in FIG. 4, the counter value corresponding to the battery block 12 of the battery No. “k−1” is set to “2”, and the life flag is set. Further, the counter value corresponding to the battery block 12 of the battery No. “k + 1” is set to “2”, and the abnormality flag is set. In the example shown in FIG. 4, information related to the date and time when the life flag and the abnormality flag are set is also stored.

  Information obtained by the processing of FIG. 2 can be notified to a user or the like. As means for providing information to the user or the like, for example, there are a display and an audio output. Further, the display content of the display can be recorded on paper using a printer or the like. On the other hand, the content of information can be changed according to the target person who provides information. Specifically, the content of information can be switched by selecting a target person.

  FIG. 5 shows information (an example) provided to the user in the process of FIG. The information shown in FIG. 5 can be displayed on a display mounted on the vehicle, for example. Examples of the display include a display used in a navigation system and a display that displays a vehicle speed and the like. When the count value is set to “1”, the information shown in FIG. 5A is displayed, and then the information shown in FIG. 5B is displayed. When the process of step S106 or step S107 in FIG. 2 is completed, the information shown in FIG. 5C is displayed.

  FIG. 6 shows information (an example) provided to the store in the process of FIG. The information shown in FIG. 6 can be displayed on, for example, a display mounted on the vehicle. When the count value is set to “1”, the information shown in FIG. 6A is displayed, and then the information shown in FIG. 6B is displayed. When the process of step S106 or step S107 in FIG. 2 is completed, the information shown in FIG. 6C is displayed.

  FIG. 7 shows information (an example) provided to the manufacturer in the process of FIG. The information shown in FIG. 7 can be displayed on, for example, a display mounted on the vehicle. When the count value is set to “1”, the information shown in FIGS. 7A and 7B is displayed. When the process of step S106 or step S107 in FIG. 2 is completed, the information shown in FIG. 7C is displayed.

  According to the present embodiment, before determining the life state and the abnormal state, it is determined twice whether or not the unit cell 11 is in a deteriorated state. By performing the deterioration state determination twice, the deterioration state determination accuracy can be improved. Further, by considering the interval of the date and time (T1, T2) at which the deterioration state is determined, it is possible to distinguish whether the deterioration state of the unit cell 11 is a life state or an abnormal state.

  In the present embodiment, in the process of step S105 in FIG. 2, the life state and the abnormal state are determined based on the interval between the dates T1 and T2, but the present invention is not limited to this. For example, the travel distance of the vehicle when the count value is set to “1” and “2” can be stored, and the life state and the abnormal state can be determined based on the difference between the travel distances. Specifically, when the difference in travel distance is shorter than the guaranteed distance, an abnormal state can be determined, and when the difference in travel distance is longer than the guaranteed distance, the life state can be determined. The guaranteed distance corresponds to the above-described warranty period, and is a reference for determining whether the unit cell 11 is in a life state or an abnormal state. The guaranteed distance can be appropriately set based on the travel distance of the vehicle when the unit cell 11 reaches the end of its life.

  A modification of this embodiment will be described with reference to FIG. FIG. 8 is a flowchart corresponding to FIG. The same processes as those described in FIG. 2 are denoted by the same reference numerals. The processing different from FIG. 2 will be mainly described.

  If it is determined in step S102 that there is a battery block 12 (single cell 11) in a deteriorated state, the controller 22 performs the process of step S108. In step S108, the count value corresponding to the deteriorated battery block 12 is incremented. When the count value is set to “2”, the timer measurement time T3 at this time is stored in the memory 22a. The measurement time T3 is a time from when the assembled battery 10 is used for the first time until the count value is set to “2”, and can be measured by a timer.

  In step S109, the controller 22 determines whether or not the measurement time T3 is longer than the guaranteed period. The guarantee period here is different from the guarantee period used in step S105 of FIG. Specifically, the warranty period is the lifetime of the unit cell 11, and the lifetime can be determined based on past actual measurement values of the unit cell 11. When the measurement time T3 is shorter than the guaranteed period, the controller 22 sets an abnormality flag in step S106. When the measurement time T3 is longer than the guaranteed period, the controller 22 sets a life flag in step S107.

  In the flowchart shown in FIG. 8, the abnormal state and the life state of the battery block 12 (unit cell 11) are determined based on the measurement time T3, but the present invention is not limited to this. For example, the abnormal state and the life state of the battery block 12 (unit cell 11) can be determined based on the travel distance of the vehicle until the count value is set to “2”. If the vehicle on which the assembled battery 10 is mounted is an electric vehicle, the usage period of the assembled battery 10 and the travel distance of the vehicle are in a proportional relationship. Therefore, based on the travel distance of the vehicle, the battery block 12 (unit cell 11) is abnormal. The state and life state can be determined. Further, the abnormal state and the life state of the battery block 12 (unit cell 11) can also be determined based on the measurement time T3 and the travel distance of the vehicle.

  A second embodiment of the present invention will be described. About the member which has the same function as the member demonstrated in Example 1, detailed description is abbreviate | omitted using the same code | symbol.

  As shown in FIG. 9, the controller 22 controls the driving of the air conditioner 31 mounted on the vehicle. The air conditioner 31 is used to adjust the temperature in the passenger compartment, and operates by receiving power from the assembled battery 10. Specifically, the air conditioner 31 supplies cooling air to the passenger compartment if the temperature in the passenger compartment increases, and supplies warmed air to the passenger compartment if the temperature in the passenger compartment decreases. can do. The passenger compartment is a space where passengers get on. An intake duct 33 and an exhaust duct 34 are connected to the assembled battery 10. The intake port of the intake duct 33 faces the vehicle interior, and air in the vehicle interior is taken into the intake duct 33.

  The intake duct 33 is provided with a fan 32. By driving the fan 32, air in the vehicle compartment can be taken into the intake duct 33. The controller 22 controls driving of the fan 32. The air taken into the intake duct 33 is guided to the assembled battery 10 and used for temperature adjustment of the assembled battery 10. Specifically, when the assembled battery 10 is generating heat, the temperature rise of the assembled battery 10 can be suppressed by introducing cooling air to the assembled battery 10. Further, when the assembled battery 10 is excessively cooled, the temperature drop of the assembled battery 10 can be suppressed by introducing the heating air to the assembled battery 10.

  The air used for temperature adjustment of the assembled battery 10 moves through the exhaust duct 34 and is discharged to the outside of the vehicle. In the present embodiment, the fan 32 is provided in the intake duct 33, but the fan 32 may be provided in the exhaust duct 34. Even in this case, the air in the passenger compartment can be guided to the assembled battery 10 by driving the fan 32.

  The assembled battery 10 is provided with a temperature sensor 27, and detection information of the temperature sensor 27 is output to the controller 22. Only one temperature sensor 27 or a plurality of temperature sensors 27 may be provided. When a plurality of temperature sensors 27 are used, a specific temperature (for example, an upper limit value or a lower limit value) among a plurality of detected temperatures is used as a detected temperature of the assembled battery 10, or an average value of a plurality of detected temperatures is used. Can be used. Further, detection information of the voltage sensor 21 is output to the controller 22. As described in the first embodiment, the voltage sensor 21 detects the voltage of each battery block 12.

  In the present embodiment, the processing shown in FIG. 10 is performed using the air conditioner 31 and the fan 32 before determining the deterioration state of the unit cell 11. The process shown in FIG. 10 is executed by the controller 22.

  When the ignition switch is turned on in step S201 and the vehicle is ready to run (READY_ON) in step S202, the controller 22 drives the air conditioner 31 and the fan 32 in step S203. The driving amounts of the air conditioner 31 and the fan 32 can be set in advance. By driving the air conditioner 31, air for temperature adjustment is supplied to the vehicle interior, and by driving the fan 32, the air in the vehicle interior is guided to the assembled battery 10.

  In step S204, the controller 22 determines whether or not the detected temperature of the assembled battery 10 is within a predetermined temperature range based on the output of the temperature sensor 27. When the temperature of the assembled battery 10 (unit cell 11) is too high or too low, the deterioration state of the unit cell 11 may not be accurately determined. Therefore, in this embodiment, the temperature of the unit cell 11 is adjusted using the air conditioner 31 and the fan 32 so that the temperature of the unit cell 11 falls within a temperature range suitable for determining the deterioration state of the unit cell 11. It is adjusting. The predetermined temperature range can be set as appropriate.

  In step S204, if the temperature of the assembled battery 10 is not within the predetermined temperature range, the controller 22 continues to drive the air conditioner 31 and the fan 32. On the other hand, if the detected temperature of the assembled battery 10 falls within the predetermined temperature range, the controller 22 stops driving the fan 32 in step S205.

  In step S <b> 206, the controller 22 determines whether or not the voltage of the battery block 12 has reached a preset lower limit value based on the output of the voltage sensor 21. The lower limit value is a lower limit voltage used in charge / discharge control of the battery pack 10. Here, charging / discharging of the assembled battery 10 is controlled so that the voltage of the battery block 12 falls within the range of the upper limit voltage and the lower limit voltage. When the voltage of the battery block 12 reaches the lower limit value, the controller 22 stops driving the air conditioner 31 in step S207.

  When a nickel metal hydride battery is used as the single battery 11, the memory effect can be eliminated by causing the voltage of the battery block 12 to reach the lower limit value. When a lithium ion battery is used as the single battery 11, the voltage of the battery block 12 does not have to reach the lower limit value. That is, the temperature of the unit cell 11 may be adjusted only.

  In the present embodiment, the voltage of the battery block 12 is made to reach the lower limit value, but is not limited thereto. Specifically, the voltage of the battery block 12 can reach an upper limit value. In this case, it is necessary to connect a charger to the assembled battery 10 and supply power to the assembled battery 10 from an external power source. The air conditioner 31 needs to be operated using a power source different from that of the assembled battery 10.

  A modification of this embodiment will be described with reference to FIG. In the present embodiment, the assembled battery 10 is used as a drive source of the air conditioner 31, and the assembled battery 10 is discharged by driving the air conditioner 31. In this modification, an external device is connected to the assembled battery 10 to discharge the assembled battery 10.

  In step S301, the assembled battery 10 is discharged in a state where the assembled battery 10 is connected to an external device. The controller 22 drives the fan 32. By driving the fan 32, the air in the passenger compartment is supplied to the assembled battery 10, and the temperature of the assembled battery 10 is adjusted.

  In step S302, the controller 22 determines whether or not the detected temperature of the assembled battery 10 is within a predetermined temperature range based on the output of the temperature sensor 27. If the temperature of the assembled battery 10 is not within the predetermined temperature range, the discharging of the assembled battery 10 and the driving of the fan 32 are continued. If the detected temperature of the assembled battery 10 is within the predetermined temperature range, the controller 22 stops driving the fan 32 in step S303.

  In step S304, the controller 22 determines whether or not the voltage of the battery block 12 has reached a preset lower limit value based on the output of the voltage sensor 21. Here, since the discharge of the assembled battery 10 continues, the voltage of the battery block 12 decreases. When the voltage of the battery block 12 reaches the lower limit value, the controller 22 stops the discharge of the assembled battery 10 in step S305.

  A third embodiment of the present invention will be described. About the member which has the same function as the member demonstrated in Example 1, 2, the same code | symbol is used and detailed description is abbreviate | omitted.

  In this embodiment, the deterioration state of the unit cell 11 is determined by driving the air conditioner 31 that uses the assembled battery 10 as a power source. This process will be described with reference to the flowchart shown in FIG. The process shown in FIG. 12 is executed by the controller 22. 12 can be performed when the ignition switch is turned on and the vehicle is ready to run (READY_ON).

  In step S <b> 401, the controller 22 determines whether or not to determine the deterioration state of the unit cell 11. If the user gives an instruction to determine the deterioration state, the process proceeds to step S402. This instruction can be performed, for example, by a user operating a touch panel display.

  In step S402, the controller 22 starts driving the air conditioner 31. In step S403, the controller 22 drives the air conditioner 31 based on a predetermined drive pattern. Since the assembled battery 10 is a power source for the air conditioner 31, the voltage of the assembled battery 10 changes according to the driving of the air conditioner 31. Here, as will be described later, the controller 22 can determine the deterioration state of the battery block 12 (unit cell 11) by monitoring the voltage behavior of the battery block 12 based on the output of the voltage sensor 21. it can. The drive control of the air conditioner 31 will be described later.

  In step S <b> 404, the controller 22 determines the deterioration state of the battery block 12 (unit cell 11) based on the voltage behavior of the battery block 12 when driving control of the air conditioner 31 is performed. Details of the determination of the deterioration state will be described later. When the determination of the deterioration state of the battery block 12 (unit cell 11) is completed, the controller 22 stops the driving of the air conditioner 31 in step S405. Here, it is possible to determine whether or not the battery block 12 is in a deteriorated state by driving the air conditioner 31 for a predetermined period. And when the predetermined period passes, the drive of the air conditioner 31 can be stopped.

  Next, drive control of the air conditioner 31 will be described with reference to FIGS. 13 and 14. Here, FIG. 13 shows the voltage behavior of the plurality of battery blocks 12 accompanying the driving of the air conditioner 31 when the assembled battery 10 is in the initial state. FIG. 14 shows the voltage behavior of the plurality of battery blocks 12 accompanying the driving of the air conditioner 31 when the specific battery block 12 is in a deteriorated state.

  In the present embodiment, the driving level of the air conditioner 31 is set to two levels of “H” and “L”. When the driving level is “H”, the driving level is “L”. The battery pack 10 is discharged at a high rate. As shown in FIG. 13, the air conditioner 31 is driven while the drive level is alternately changed between “H” and “L”. In this embodiment, the period t1 in which the drive level is set to “H” and the period t2 in which the drive level is set to “L” are equal.

  In the present embodiment, the driving level of the air conditioner 31 is set to only two levels H and L, but is not limited to this. When three or more levels are set as the driving level of the air conditioner 31, two of these levels may be selected. For example, the level at which the driving amount of the air conditioner 31 shows the maximum value and the level at which the driving value of the air conditioning device 31 shows the minimum value can be selected.

When the air conditioner 31 is driven based on the drive pattern shown in FIG. 13 and the input / output characteristics of the battery block 12 (unit cell 11) vary, the voltage behavior of the battery block 12 (unit cell 11). Variation occurs. Further, when the deterioration of the battery block 12 proceeds, the maximum voltage difference in the plurality of battery blocks 12 widens. As shown in FIG. 13, when the assembled battery 10 is in the initial state, the maximum voltage difference in the plurality of battery blocks 12 is ΔV ₀ . On the other hand, when the deteriorated battery block 12 exists, the voltage value in the deteriorated battery block 12 is lower than the voltage values of the other battery blocks 12, and as shown in FIG. The maximum voltage difference at 12 is ΔVmax. The voltage difference ΔVmax can be set in advance based on experiments or the like.

  The controller 22 monitors the voltages of the plurality of battery blocks 12 while driving the air conditioner 31, and can determine that there is a deteriorated battery block 12 when the voltage difference ΔVmax occurs. That is, it is possible to determine that the battery block 12 showing a voltage lower than the voltage of the other battery block 12 by the voltage difference ΔVmax is in a deteriorated state.

  On the other hand, by monitoring the behavior of the voltage of the battery block 12, it is possible to determine whether or not there is a deteriorated battery block 12. Specifically, as shown in FIG. 15, when the air conditioner 31 is driven while switching the drive level of the air conditioner 31 between “H” and “L”, depending on whether or not it is in a deteriorated state, The voltage behavior of the battery block 12 changes. In FIG. 15, the solid line indicates the voltage behavior of the battery block 12 in the normal state, and the dotted line indicates the voltage behavior of the battery block 12 in the deteriorated state.

  As shown in FIG. 15, when the battery block 12 in a deteriorated state exists, the voltage is decreased by the voltage difference ΔVmax with respect to the normal battery block 12 voltage. For this reason, the battery block 12 in a deteriorated state can be specified by detecting the voltage drop amount ΔVmax.

  On the other hand, as shown in FIG. 16, by continuing to drive the air conditioner 31 at the drive level H, it is possible to determine whether or not the battery block 12 is in a deteriorated state. If the air conditioner 31 is continuously driven, the voltage of the battery block 12 continues to drop by continuing to discharge the assembled battery 10. Here, if there is a battery block 12 in a degraded state, the voltage of the battery block 12 starts to drop at an earlier timing than the voltages of the other battery blocks 12.

  In FIG. 16, the solid line indicates the voltage behavior of the battery block 12 in the normal state, and the dotted line indicates the voltage behavior of the battery block 12 in the deteriorated state. The battery block 12 in the deteriorated state starts to drop at a timing earlier by Δtmax than the battery block 12 in the normal state. By monitoring the behavior of this voltage, it can be determined whether or not the battery block 12 is in a deteriorated state.

  On the other hand, as shown in FIG. 17, it is possible to determine whether or not the battery block 12 is in a deteriorated state by monitoring the IV characteristics (internal resistance) of the battery block 12. In FIG. 17, the solid line indicates the IV characteristics of the battery block 12 in the normal state, and the dotted line indicates the IV characteristics of the battery block 12 in the abnormal state. The characteristics shown in FIG. 17 indicate voltage changes of the battery block 12 when pulse discharge is performed at different current values I1, I2, and I3 as shown in FIG.

  When the battery block 12 is in a deteriorated state, the amount of voltage drop is larger than that of the battery block 12 in a normal state. Here, if a reference (IV characteristic) for determining the deterioration state is determined in advance, it can be determined whether or not the battery block 12 is in the deterioration state.

  In the present embodiment, the air conditioner 31 is driven to change the voltage of the battery block 12 to determine the deterioration state of the battery block 12, but the present invention is not limited to this. That is, instead of the air conditioner 31, an electronic device that operates using the assembled battery 10 as a power source can be used. As this electronic device, for example, there is an audio device mounted on a vehicle.

10: assembled battery (power storage device) 11: single battery 12: battery block 21: voltage sensor 22: controller 23a, 23b: system main relay 24: DC / DC converter 25: inverter 26: motor / generator 27: temperature sensor 31: Air conditioner (electronic equipment) 32: Fan 33: Intake duct 34: Exhaust duct

Claims (16)

A diagnostic device for determining a deterioration state of a plurality of power storage units constituting a power storage device,
A voltage sensor for detecting a voltage of each power storage unit;
A controller for determining whether or not each power storage unit is in a deteriorated state based on a detection result of the voltage sensor;
A memory for storing information on the deterioration state when the controller determines that the power storage unit is in a deterioration state;
Have
The controller determines whether the power storage unit is in an abnormal state or a life state by using the number of times of deterioration state determination among the information stored in the memory.   The controller determines that the power storage unit is in an abnormal state when the number of determinations determined that the power storage unit is in a deteriorated state is a plurality of times within a predetermined period, and the number of determinations exceeds the predetermined period The diagnosis apparatus according to claim 1, wherein when the number of times is reached several times, it is determined that the power storage unit is in a life state. The controller is
It is determined whether the time interval when the deterioration state is determined for the first time and when the deterioration state is determined for the second time exceeds a predetermined period,
When the time interval exceeds the predetermined period, it is determined that the power storage unit is in a life state, and when the time interval does not exceed the predetermined period, it is determined that the power storage unit is in an abnormal state. The diagnostic apparatus according to claim 2. The controller is
Determine whether the elapsed time until the second determination of the deterioration state exceeds the predetermined period,
When the elapsed time exceeds the predetermined period, it is determined that the power storage unit is in a life state, and when the elapsed time does not exceed the predetermined period, it is determined that the power storage unit is in an abnormal state. The diagnostic apparatus according to claim 2.   The controller sets a flag indicating an abnormal state when determining that the controller is in the abnormal state, and sets a flag indicating a life state when determining that the controller is in the life state. 5. The diagnostic device according to any one of 4. A temperature sensor for detecting the temperature of the power storage device;
The controller drives a fan for introducing temperature adjusting air to the power storage device, and determines the deterioration state when a temperature detected by the temperature sensor is within a predetermined temperature range. The diagnostic apparatus according to claim 1, wherein the diagnostic apparatus is characterized in that: The diagnostic device according to any one of claims 1 to 6,
An electronic device that operates by receiving electric power from the power storage device,
The vehicle, wherein the controller determines the deterioration state based on a voltage change of the power storage unit accompanying driving of the electronic device.   The vehicle according to claim 7, wherein the electronic device is an air conditioner for adjusting a temperature in a passenger compartment. A diagnostic device according to claim 6;
An air conditioner that operates by receiving electric power from the power storage device and adjusts the temperature in the passenger compartment,
The vehicle, wherein the controller determines the deterioration state after driving the air conditioner to discharge the power storage unit. A diagnostic method for determining a deterioration state of a plurality of power storage units constituting a power storage device,
Determining whether each power storage unit is in a deteriorated state based on a detection result of a voltage sensor that detects a voltage of each power storage unit;
Storing the information on the deterioration state in a memory when it is determined that the power storage unit is in a deterioration state;
Of the information stored in the memory, using the number of times of deterioration state determination, determining whether the power storage unit is in an abnormal state or a life state;
A diagnostic method characterized by comprising:   When the number of times of determination that the power storage unit is in a deteriorated state is a plurality of times within a predetermined period, it is determined that the power storage unit is in an abnormal state, and when the number of times of determination exceeds the predetermined time, a plurality of times The diagnosis method according to claim 10, wherein when it becomes, the power storage unit is determined to be in a life state. It is determined whether the time interval when the deterioration state is determined for the first time and when the deterioration state is determined for the second time exceeds a predetermined period,
When the time interval exceeds the predetermined period, it is determined that the power storage unit is in a life state, and when the time interval does not exceed the predetermined period, it is determined that the power storage unit is in an abnormal state. The diagnostic method according to claim 11. Determine whether the elapsed time until the second determination of the deterioration state exceeds the predetermined period,
When the elapsed time exceeds the predetermined period, it is determined that the power storage unit is in a life state, and when the elapsed time does not exceed the predetermined period, it is determined that the power storage unit is in an abnormal state. The diagnostic method according to claim 11.   A fan for guiding temperature adjusting air to the power storage device is driven, and the deterioration state is determined when the temperature of the power storage device detected by a temperature sensor is within a predetermined temperature range. The diagnostic method according to any one of claims 10 to 13, wherein:   15. The deterioration state is determined based on a voltage change of the power storage unit accompanying driving of an electronic device that operates by receiving power from the power storage device. The diagnostic method described. The diagnostic method according to claim 15, wherein the electronic device is an air conditioner that is mounted on a vehicle and adjusts the temperature in the passenger compartment.

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