JP2011240896A - Battery control device and vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the remaining capacity or the degree of deterioration of a secondary battery which is inbuilt in a vehicle, with greater precision.SOLUTION: A battery control device includes: a discharge control unit which, when the running of a vehicle is stopped, discharges the secondary battery which is inbuilt in the vehicle until the voltage value of the secondary battery reaches a predetermined discharge termination voltage value; a first remaining capacity identification unit which identifies the remaining capacity of the secondary battery prior to discharge by the discharge control unit as a first remaining capacity on the basis of a predetermined identification method; a discharge amount measurement unit which measures the discharge amount of the secondary battery; a second remaining capacity identification unit which identifies the remaining capacity of the secondary battery prior to discharge by the discharge control unit as a second remaining capacity on the basis of the discharge amount measured by the discharge amount measurement unit during discharge by the discharge control unit; and an identification method revision unit which revises the identification method on the basis of the difference between the first remaining capacity and the second remaining capacity.

Description

  The present invention relates to a battery control device that controls a secondary battery mounted on a vehicle.

Conventionally, various methods for detecting a remaining capacity of a secondary battery mounted on a vehicle or a deterioration state of the secondary battery have been proposed.
Patent Document 1 JP 2006-194789 A Patent Document 2 JP 2008-179284 A

  The remaining capacity of the secondary battery also changes, for example, depending on the difference in the internal resistance of the secondary battery, and the internal resistance of the secondary battery also changes with temperature. Further, when the vehicle is in operation, the surrounding environment changes relatively frequently, and the temperature of the secondary battery is difficult to be constant. Therefore, it is not easy to accurately detect the remaining capacity or the deterioration state of the secondary battery mounted on the vehicle.

  The present invention makes it possible to more accurately detect the remaining capacity or the degree of deterioration of a secondary battery mounted on a vehicle.

  In one aspect of the battery control apparatus according to the present invention, the secondary battery is discharged until the voltage value of the secondary battery mounted on the vehicle reaches a predetermined discharge end voltage value while the vehicle is stopped. A discharge control unit, a first remaining capacity specifying unit that specifies the remaining capacity of the secondary battery before discharging by the discharge control unit as a first remaining capacity based on a predetermined specifying method, and a discharge amount of the secondary battery Based on the discharge amount measured by the discharge amount measuring unit between the discharge amount measuring unit to be measured and the discharge by the discharge control unit, the remaining capacity of the secondary battery before the discharge by the discharge control unit is specified as the second remaining capacity A second remaining capacity specifying unit, and a specifying method correcting unit that corrects the specifying method based on a difference between the first remaining capacity and the second remaining capacity.

  In the battery control apparatus, the first remaining capacity specifying unit specifies the remaining capacity of the secondary battery during operation of the vehicle based on the specifying method, and determines the remaining capacity of the secondary battery immediately before the operation of the vehicle is stopped first. It may be specified as the remaining capacity.

  The battery control device may further include a temperature acquisition unit that acquires the temperature of the secondary battery, and the specifying method correction unit may correct the specifying method based on the difference and the temperature.

  In the above battery control device, the battery control device further includes a temperature holding unit that holds the temperature during discharge by the discharge control unit acquired by the temperature acquisition unit, and the specifying method correction unit differs from the temperature during discharge held by the temperature holding unit. The identification method may be corrected based on the above.

  In the above battery control device, the temperature holding unit further holds the temperature during operation of the vehicle acquired by the temperature acquisition unit, and the specifying method correction unit is the temperature during discharge held by the temperature holding unit, during operation The specific method may be corrected based on the temperature and the difference.

  In the battery control device, the first remaining capacity specifying unit calculates the discharge amount of the secondary battery during the operation of the vehicle measured by the discharge amount measurement unit, at a predetermined end-of-charge voltage value of the secondary battery. By subtracting from the charged amount, the remaining capacity of the secondary battery during operation of the vehicle may be specified.

  The battery control device measures the charge amount of the secondary battery when the secondary battery is charged until the voltage value of the secondary battery reaches a predetermined charge end voltage value from the discharge end voltage value. A charge amount measuring unit and a full charge amount specifying unit that specifies a full charge amount based on the charge amount measured by the charge amount measuring unit are further provided, and the first remaining capacity specifying unit is specified by the full charge amount specifying unit The remaining capacity may be specified by subtracting the discharge amount from the full charge amount.

  Said battery control apparatus may further be provided with the transmission part which transmits the data which show a difference to the server which collects the information regarding a secondary battery.

  In the battery control apparatus, the discharge control unit may discharge the secondary battery after a predetermined period has elapsed after the vehicle has stopped operating.

  In one aspect of the battery control device according to the present invention, a secondary battery mounted on a vehicle and a load device that operates by receiving power supply from the secondary battery during operation of the vehicle are stopped. A connection control unit that is electrically connected to the inside, and after the secondary battery and the load device are electrically connected by the connection control unit, the voltage value of the secondary battery at two different timings is set to the first voltage value and the first voltage value. A voltage value acquiring unit that acquires the two voltage values; and a deterioration state specifying unit that specifies a deterioration state of the secondary battery based on the first voltage value and the second voltage value.

  The battery control device further includes a correlation holding unit that holds a correlation between the first voltage value, the second voltage value, and the deterioration state of the secondary battery, and the deterioration state specifying unit is based on the correlation. The deterioration state of the secondary battery corresponding to the first voltage value and the second voltage value acquired by the voltage value acquisition unit may be specified.

  In the above battery control device, the load device is a motor serving as a drive source for the vehicle, and the connection control unit electrically connects the secondary battery and the motor, and supplies current to the excitation coil of the motor. Also good.

  The battery control apparatus may further include a transmission unit that transmits information indicating the deterioration state of the secondary battery specified by the deterioration state specifying unit to a server that collects information related to the secondary battery.

  In one aspect of the vehicle according to the present invention, the battery control device described above and a secondary battery are provided.

  It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

It is a figure showing the schematic structure of the electric vehicle concerning this embodiment. It is a figure which shows the functional block of battery ECU. It is a figure which shows the mode of the voltage drop of a secondary battery. It is a figure which shows an example of the temperature information which a temperature holding part hold | maintains. It is a flowchart which shows the procedure which correct | amends a specific method. It is a flowchart which shows the procedure which pinpoints the deterioration state of a secondary battery.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 shows a schematic configuration of an electric vehicle according to the present embodiment. In the present embodiment, an electric vehicle that is one of the electric vehicles will be described as an example. However, the present embodiment can also be applied to other electric vehicles including a motor generator as a drive source.

  The electric vehicle is equipped with the secondary battery 10. The secondary battery 10 may be a nickel metal hydride secondary battery or a lithium ion secondary battery. The secondary battery 10 has a plurality of battery blocks connected in series and in parallel. Each of the plurality of battery blocks includes a plurality of battery modules electrically connected in series and in parallel. The battery module includes a plurality of single cells (cells) electrically connected in series and in parallel. The configuration of the secondary battery 10 is not limited to the above.

  The electric power from the secondary battery 10 is supplied to the motor generator 40 via the relay 20 and the inverter 30. The power from the motor generator 40 is transmitted to the wheels via the drive shaft. Further, the regenerative power generated by the motor generator 40 when the electric vehicle decelerates is charged to the secondary battery 10 via the inverter 30 and the relay 20. The configuration of the electric vehicle is not limited to the above. For example, an electric vehicle of an in-wheel motor system in which a motor is disposed in a wheel may be used.

  The electric vehicle includes a battery ECU 100, a main ECU 200, and a brake ECU 300. The battery ECU 100 acquires the voltage value V between the terminals of the secondary battery 10 via the voltage sensor 60. Battery ECU 100 acquires charge / discharge current value I including charge current Ic and discharge current Id for secondary battery 10 via current sensor 62. Further, the battery ECU 100 acquires the temperature T of the surface of the secondary battery 10 via the temperature sensor 64. In the present embodiment, an example in which one voltage sensor 60 and one temperature sensor 64 are provided for the secondary battery 10 will be described. However, the voltage sensor 60 and / or the temperature sensor 64 may be provided for each battery block, each battery module, or each cell constituting the secondary battery 10.

  The battery ECU 100 specifies the remaining capacity, the charged state, or the deteriorated state of the secondary battery 10 based on information such as the voltage value V, the charging / discharging current value I including the charging current Ic and the discharging current Id, and the temperature T. , Together with information such as voltage value V, charge / discharge current value I, temperature T, etc., is transmitted to main ECU 200. The main ECU 200 controls the inverter 30 and the like based on information from the battery ECU 100 and the like in order to control operations such as running and stopping of the electric vehicle. The brake ECU 300 receives an input of a brake pedal signal via the brake pedal and controls the brake system 50 based on the brake pedal signal, thereby decelerating the electric vehicle.

  When the electric vehicle decelerates, main ECU 200 controls inverter 30 and the like to perform regenerative control for charging rechargeable battery 10 with regenerative energy generated in motor generator 30. The battery ECU 100 measures the charge amount based on the voltage value V, the charge / discharge current I, and the like even during charging of the secondary battery 10 by the regenerative control, and specifies the remaining capacity of the charge amount secondary battery 10.

  In the electric vehicle configured as described above, in order to detect the remaining capacity of the secondary battery 10 more accurately, the battery ECU 100 discharges the secondary battery 10 while the electric vehicle is stopped and is measured during the discharge. Based on the discharged amount, the predetermined specifying method is corrected by correcting the correction coefficient k given to the function for specifying the remaining capacity, the value shown in the lookup table, and the like. In addition, during operation stop means the period when the start switch for starting an electric vehicle is an OFF state. Also, “operating” means a period in which the start switch is in an ON state.

  Further, the battery ECU 100 electrically connects the secondary battery 10 and the motor generator 40 in a state where the brake system 50 is operated and the rotation of the motor generator 40 is fixed while the electric vehicle is stopped. A high load is applied to the secondary battery 10. Battery ECU 100 specifies the deterioration state of secondary battery 10 based on the amount of change in voltage value V of secondary battery 10 when a high load is applied.

  FIG. 2 shows functional blocks of the battery ECU 100. The charge amount measuring unit 102 measures the charge amount charged in the secondary battery 10 based on the charging current Ic, the voltage value V, and the charging time Hc. The charge amount measuring unit 102 may use an average value, a mean square value, or a moving average value as the charging current I and the voltage value V. The charge amount measuring unit 102 may measure the charge amount by integrating a value obtained by multiplying the charge current I and the voltage value V by the charge time Hc. The full charge amount specifying unit 104 specifies the charge amount until the voltage value V of the secondary battery 10 reaches the charge end voltage value from the state of the discharge end voltage value determined. Specify the amount of charge. The full charge amount specifying unit 104 specifies the charge amount until the voltage value of any cell, battery module, or battery block constituting the secondary battery 10 reaches the end-of-charge voltage value. The full charge amount of the battery 10 may be specified.

  The discharge amount measuring unit 106 measures the discharge amount discharged by the secondary battery 10 based on the discharge current Id, the voltage value V, and the discharge time Hd. The charge amount measuring unit 102 may use an average value, a mean square value, or a moving average value as the discharge current Id and the voltage value V. The discharge amount measuring unit 106 may measure the discharge amount by integrating a value obtained by multiplying the discharge current Id and the voltage value V by the discharge time Hd. The first remaining capacity specifying unit 108 specifies the remaining capacity of the secondary battery 10 during operation of the electric vehicle. More specifically, the first remaining capacity specifying unit 108 specifies the remaining capacity by subtracting the discharge amount provided from the discharge amount measuring unit 106 from the full charge amount provided from the full charge amount specifying unit 104. To do. The remaining capacity holding unit 112 holds the remaining capacity specified by the first remaining capacity specifying unit 108. The discharge amount measuring unit 106 registers the remaining capacity specified immediately before the electric vehicle stops operating, that is, immediately before the start switch is turned off, in the remaining capacity holding unit 112 as the first remaining capacity Ca before discharging.

  The second remaining capacity specifying unit 110 discharges the amount of discharge measured by the discharge amount measuring unit 106 while the discharge control unit 124 described later discharges the secondary battery 10 while the electric vehicle is stopped. It is specified as the second remaining capacity Cb of the previous secondary battery.

  In order to stabilize the state of the secondary battery 10, the discharge controller 124 waits for a predetermined reference period, for example, 2 hours after the electric vehicle stops operating, and after the reference period has elapsed, the voltage of the secondary battery 10 is The secondary battery 10 is discharged until the value V reaches the discharge end voltage value. Note that the discharge control unit 124 sets the voltage value V of the secondary battery 10 to the end of discharge when the voltage value of any cell, battery module, or battery block constituting the secondary battery 10 reaches the end of discharge voltage value. It may be determined that the voltage value has been reached. For example, the discharge control unit 124 connects the secondary battery 10 and the motor generator 40 in a state where the clutch is disengaged or in a state where the brake is applied, and causes the secondary current to flow through the excitation coil included in the motor generator 40. The battery 10 is discharged. When the electric vehicle can supply power to an external electrical device as a power storage device, the discharge control unit 124 causes the electric vehicle to function as a power storage device and supplies power from the secondary battery 10 to the external electrical device. Thus, the secondary battery 10 may be discharged.

  The temperature acquisition unit 114 acquires the temperature T of the surface of the secondary battery 10 from the temperature sensor 64 periodically, for example, every second, and registers it in the temperature holding unit 116 together with time information indicating the acquired time.

  The identification method correction unit 118 corrects the identification method based on the first remaining capacity Ca, the second remaining capacity Cb, and the temperature T immediately before the secondary battery 10 is discharged by the discharge control unit 124. The correction coefficient k used when the specifying unit 108 calculates the remaining capacity is specified. Here, the first remaining capacity Ca immediately before the secondary battery 10 is discharged by the discharge control unit 124 and the second remaining capacity corresponding to the discharge amount associated with the discharge of the secondary battery 10 by the discharge control unit 124. Cb is the same value. However, the remaining capacity of the secondary battery 10 changes depending on, for example, the difference in the internal resistance of the secondary battery 10, and the internal resistance of the secondary battery 10 also changes depending on the temperature. Further, when the electric vehicle is in operation, the secondary battery 10 is repeatedly charged and discharged. In addition, there are relatively many changes in the surrounding environment, and the temperature of the secondary battery 10 is difficult to be constant. Therefore, the first remaining capacity Ca specified by the first remaining capacity specifying unit 108 during operation of the electric vehicle is changed to the second remaining capacity Cb specified by the second remaining capacity specifying unit 110 while the operation of the electric vehicle is stopped. Errors are more likely to occur. Therefore, the specifying method correction unit 118 calculates the difference ΔC between the first remaining capacity Ca and the second remaining capacity Cb, specifies the correction coefficient k based on the difference ΔC, and causes the correction coefficient holding unit 122 to hold the correction coefficient k.

  The identification method correction unit 118 may use the difference ΔC as the correction coefficient k. In this case, the first remaining capacity specifying unit 108 adds the difference ΔC to the value obtained by subtracting the discharge amount provided from the discharge amount measuring unit 106 from the full charge amount, thereby the secondary battery in which the electric vehicle is operating. May be calculated.

  Further, as described above, the remaining capacity may change depending on the temperature T of the secondary battery 10. Therefore, the specifying method correction unit 118 uses the temperature T of the secondary battery 10 in operation, the temperature T of the secondary battery 10 being discharged by the discharge control unit 124, and the difference ΔC as parameters, and performs a statistical classification algorithm or data mining. Thus, a correction coefficient k that reduces the difference ΔC may be specified. That is, the specifying method correction unit 118 continuously counts the temperature T of the secondary battery 10 in operation, the temperature T of the secondary battery 10 being discharged by the discharge control unit 124, and the difference ΔC, and zeroes the difference ΔC. The correction coefficient k may be updated sequentially based on a statistical prediction. The specifying method correction unit 118 may specify the correction coefficient k for each temperature change pattern of the operating secondary battery 10 and each driving pattern of the electric vehicle. Note that the temperature T of the secondary battery 10 in operation and the temperature T of the secondary battery 10 being discharged by the discharge control unit 124 may be an average temperature measured during each period.

  In order to identify the deterioration state of the secondary battery 10, the connection control unit 150 closes the relay 20 while the rotation of the motor generator 40 is fixed by the brake system 50 while the electric vehicle is stopped. Secondary battery 10 and motor generator 40 are electrically connected. When the secondary battery 10 and the motor generator 40 are electrically connected while the rotation of the motor generator 40 is fixed, a high load is applied to the secondary battery 10. By setting the secondary battery 10 to a high load state, the deterioration state of the secondary battery 10 can be specified based on so-called IR (current × internal resistance) drop. FIG. 3 shows a state of voltage drop of the secondary battery 10 that occurs when the secondary battery 10 is in a high load state. The secondary battery 10 tends to have a voltage drop as the deterioration progresses. That is, there is a high possibility that the deterioration of the secondary battery 10 is progressing as the rate of change of the voltage value V increases. Therefore, in this embodiment, the deterioration state of the secondary battery 10 is specified based on the magnitude of the change rate of the voltage value V.

  The voltage value acquisition unit 152 acquires the voltage value V of the secondary battery 10 at at least two different timings immediately after the connection control unit 150 enters the high load state, and provides it to the deterioration state specifying unit 154. To do. The correlation holding unit 156 holds the change rate of the voltage value V and the deterioration state of the secondary battery 10 in association with each other. The degradation state specifying unit 154 calculates the rate of change of the voltage value V based on the provided plurality of voltage values V, and refers to the correlation holding unit 156, so that the secondary battery corresponding to the calculated rate of change is obtained. Ten deterioration states are specified. Note that the deterioration state of the secondary battery 10 may be the remaining life of the secondary battery 10.

  The deterioration state specifying unit 154 may specify the deterioration state of the secondary battery 10 based on image data indicating the voltage waveform pattern of the secondary battery 10 as shown in FIG. For example, the correlation holding unit 156 may hold in advance image data indicating the voltage waveform pattern of the secondary battery 10 in the initial state (at the time of shipment). In this case, the deterioration state specifying unit 154 specifies the voltage waveform pattern of the secondary battery 10 when the secondary battery 10 is in a high load state, the image data corresponding to the specified voltage waveform pattern, and the above-mentioned The deterioration state of the secondary battery 10 may be specified based on the degree of coincidence by comparing the image data corresponding to the voltage waveform pattern in the initial state. In addition, the correlation holding unit 156 may hold image data of a reference voltage waveform pattern for each deterioration state of the secondary battery 10 in advance. In this case, the deterioration state specifying unit 154 specifies the voltage waveform pattern of the secondary battery 10 when the secondary battery 10 is in a high load state, and the reference voltage waveform having the highest degree of coincidence with the specified voltage waveform pattern. By specifying the pattern, the deterioration state of the secondary battery 10 may be specified. In addition, the correlation holding unit 156 may hold image data of a reference voltage waveform pattern for each deterioration state in advance for each battery block, each battery module, or each cell. In this case, when the secondary battery 10 is in a high load state, the deterioration state specifying unit 154 specifies and specifies the voltage waveform pattern of the secondary battery 10 for each battery block, each battery module, or each cell. The deterioration state may be specified for each battery block, each battery module, or each cell by specifying the reference voltage waveform pattern having the highest degree of coincidence with each voltage waveform pattern.

  The transmission unit 130 transmits information related to the state of the secondary battery 10 to a predetermined transmission destination. The information regarding the state of the secondary battery 10 includes the difference ΔC, the full charge amount of the secondary battery 10 specified by the full charge amount specifying unit 104, and the deterioration state of the secondary battery 10 specified by the deterioration state specifying unit 154. May be included. The transmission destination may be a server that collects information necessary for maintaining an electric vehicle, for example.

  FIG. 4 shows an example of temperature information held by the temperature holding unit 116. The temperature holding unit 116 holds the temperature T of the secondary battery 10 periodically acquired by the temperature acquisition unit 114, the time when the temperature T is acquired, and the operation state of the electric vehicle at the time when the temperature T is acquired in association with each other. Also good. The operation state of the electric vehicle may include start of discharge, stop of operation, start of discharge, stop of discharge and end of discharge, start of charge, end of charge and end of charge during operation. The specifying method correcting unit 118 can specify the correlation between the operation state of the electric vehicle and the temperature T of the secondary battery 10 by referring to the temperature holding unit 116.

  FIG. 5 is a flowchart showing a correction procedure of a specific method that is executed after the electric vehicle stops operating, that is, after the start switch is turned off.

  The discharge controller 124 determines whether or not the reference period has elapsed since the operation was stopped (S100). If it has elapsed, the discharge control unit 124 discharges the secondary battery 10 until the voltage value V of the secondary battery 10 reaches the end-of-discharge voltage value (S102). The discharge amount measuring unit 106 measures the discharge amount of the secondary battery 10 from when the discharge control unit 124 starts discharging the secondary battery 10 to when the discharge ends, and the second remaining capacity specifying unit 110 The measured discharge amount is specified as the second remaining capacity Cb. The specifying method correcting unit 118 refers to the remaining capacity holding unit 112 and specifies the remaining capacity specified by the first remaining capacity specifying unit 108 immediately before the operation is stopped as the first remaining capacity Ca. Further, the specifying method correction unit 118 calculates a difference ΔC between the first remaining capacity Ca and the second remaining capacity Cb, and registers the difference ΔC in the difference holding unit 120 (S106). The identification method correcting unit 118 refers to the temperature holding unit 116 and the difference holding unit 120, and based on the temperature T during operation of the electric vehicle, the temperature T during discharge, and the difference ΔC, for example, by a statistical classification algorithm or data mining Then, the correction coefficient k that can reduce the difference ΔC is specified (S108).

  As described above, in this embodiment, in order to stabilize the state of the secondary battery 10, the discharge control unit 124 stands by until a predetermined period elapses after the electric vehicle stops operating. Thereafter, the discharge control unit 124 discharges the secondary battery 10 in a relatively stable state. The discharge control unit 124 corresponds to detecting that the temperature of the secondary battery 10 has become constant, such as when the rate of change of the temperature of the secondary battery 10 becomes smaller than a predetermined rate of change. The discharge of the secondary battery 10 may be started. The second remaining capacity specifying unit 110 specifies the second remaining capacity Cb based on the amount of discharge during discharge. The second remaining capacity Cb is a value based on the amount of discharge measured by actually discharging the secondary battery 10 in a relatively stable state. Therefore, there is a high possibility that the value is more accurate than the first remaining capacity Ca. Therefore, the remaining capacity of the secondary battery 10 during operation of the electric vehicle is specified more accurately by setting the correction coefficient k such that the first remaining capacity Ca approaches the second remaining capacity Cb.

  As described above, the voltage value of the secondary battery 10 is lowered to the discharge end voltage value by the discharge control unit 124. Therefore, in order to operate the electric vehicle again, it is necessary to charge the secondary battery 10 again. Therefore, after the correction coefficient k is specified, the battery ECU 100 charges the secondary battery 10 until the voltage value V of the secondary battery 10 reaches the end-of-charge voltage value. Note that the battery ECU 100 may end the charging of the secondary battery 19 when the voltage value of any cell, battery module, or battery block constituting the secondary battery 10 reaches the charge end voltage value. Charging of the secondary battery 10 may be performed by a quick charger. Further, the full charge amount specifying unit 104 may specify the full charge amount of the secondary battery 10 when the secondary battery 10 is charged after the correction coefficient k is specified.

  FIG. 6 is a flowchart showing a procedure for specifying the deterioration state of the secondary battery 10 after the electric vehicle stops operating.

  The connection control unit 150 determines whether or not the reference period has elapsed since the operation was stopped (S200). If it has elapsed, the connection control unit 150 causes the brake ECU 300 to operate the brake system 50 via the main ECU 200 and outputs a brake signal so that the rotation of the motor generator 40 is fixed. Next, the connection control unit 150 electrically connects the secondary battery 10 and the motor generator 40 by closing the relay 20 while the rotation of the motor generator 40 is fixed. A current is passed through the excitation coil provided (S202). Note that the connection control unit 150 does not have to fix the rotation of the motor generator 40 as long as a current flows through the exciting coil and the electric vehicle can maintain the stopped state. The voltage value acquisition unit 152 is to measure the rate of voltage drop that occurs immediately after the secondary battery 10 and the motor generator 40 are electrically connected, that is, the rate of change of the voltage value of the secondary battery 10. The voltage values V of the secondary batteries 10 at a plurality of different timings are acquired and provided to the deterioration state specifying unit 154. The deterioration state specifying unit 154 calculates the rate of change of the voltage value V based on the plurality of voltage values V, and refers to the correlation holding unit 156 to determine the deterioration state of the secondary battery 10 corresponding to the calculated rate of change. Is identified (S204).

  As described above, in this embodiment, in order to stabilize the state of the secondary battery 10, the connection control unit 150 waits until a predetermined period elapses after the electric vehicle stops operating. Thereafter, the connection control unit 150 applies a high load to the secondary battery 10 in a relatively stable state, causes an IR drop to occur in the secondary battery 10, a deterioration state of the secondary battery 10, or for each battery block, The deterioration state for each battery module or each cell is specified. As described above, since the deterioration state is determined for the secondary battery 10 in a relatively stable state, the deterioration state of the secondary battery 10 or the deterioration of each battery block, each battery module, or each cell more accurately. A state is identified.

  In the above description, the example in which the correction of the specifying method and the specification of the deterioration state are individually executed has been described. However, the deterioration state of the secondary battery 10 may be specified in response to the correction coefficient k being specified and the charging of the secondary battery 10 being completed. Moreover, the correction | amendment of a specific method and specification of the deterioration state each demonstrated after the operation stop and after the reference period passed. However, the correction of the specifying method and the specification of the deterioration state may be executed immediately after the operation is stopped.

  Further, the electric power to the battery ECU 100, the main ECU 200, the brake ECU 300, and the like during the operation stop of the electric vehicle may be supplied from an auxiliary battery provided in the electric vehicle.

  Furthermore, in the present embodiment, an example in which the secondary battery 10 and the motor generator 40 are electrically connected has been described. However, a load device other than the motor generator 40 may be electrically connected to the secondary battery 10. For example, an air conditioner mounted on an electric vehicle may be used as the load device.

  When the secondary battery 10 is overcharged or overdischarged, the life of the secondary battery 10 may be shortened. Therefore, if the remaining capacity of the secondary battery 10 is accurately grasped, the secondary battery 10 can hardly be overcharged or overdischarged during operation of the electric vehicle, and the life of the secondary battery 10 can be shortened. Can be suppressed.

  In addition, since the deterioration state of the secondary battery 10 is accurately grasped, maintenance of the electric vehicle is facilitated.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  The order of execution of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior to”. It should be noted that the output can be realized in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for convenience, it means that it is essential to carry out in this order. It is not a thing.

DESCRIPTION OF SYMBOLS 10 Secondary battery 20 Relay 30 Inverter 40 Motor generator 50 Brake system 60 Voltage sensor 62 Current sensor 64 Temperature sensor 100 Battery ECU
102 charge amount measuring unit 104 full charge amount specifying unit 106 discharge amount measuring unit 108 first remaining capacity specifying unit 110 second remaining capacity specifying unit 112 remaining capacity holding unit 114 temperature acquiring unit 116 temperature holding unit 118 specifying method correcting unit 120 difference Holding unit 122 Correction coefficient holding unit 124 Discharge control unit 130 Transmission unit 150 Connection control unit 152 Voltage value acquisition unit 154 Degradation state specifying unit 156 Correlation holding unit 200 Main ECU
300 Brake ECU

Claims (14)

A discharge controller that discharges the secondary battery until the voltage value of the secondary battery mounted on the vehicle reaches a predetermined discharge end voltage value while the operation of the vehicle is stopped;
A first remaining capacity specifying unit that specifies, as a first remaining capacity, a remaining capacity of the secondary battery before discharging by the discharge control unit based on a predetermined specifying method;
A discharge amount measuring unit for measuring a discharge amount of the secondary battery;
Based on the discharge amount measured by the discharge amount measurement unit during the discharge by the discharge control unit, a second remaining capacity that specifies the remaining capacity of the secondary battery before the discharge by the discharge control unit as a second remaining capacity A capacity identification unit;
A battery control apparatus comprising: a specifying method correcting unit that corrects the specifying method based on a difference between the first remaining capacity and the second remaining capacity. The first remaining capacity specifying unit specifies the remaining capacity of the secondary battery during operation of the vehicle based on the specifying method, and determines the remaining capacity of the secondary battery immediately before stopping the operation of the vehicle. The battery control device according to claim 1 specified as a remaining capacity. A temperature acquisition unit for acquiring the temperature of the secondary battery;
The battery control device according to claim 1, wherein the specifying method correction unit corrects the specifying method based on the difference and the temperature. A temperature holding unit that holds the temperature during discharge by the discharge control unit acquired by the temperature acquisition unit;
The battery control apparatus according to claim 3, wherein the specifying method correction unit corrects the specifying method based on the temperature during the discharge held by the temperature holding unit and the difference. The temperature holding unit further holds the temperature during operation of the vehicle acquired by the temperature acquisition unit,
The battery control device according to claim 4, wherein the specifying method correction unit corrects the specifying method based on the temperature during the discharge held by the temperature holding unit, the temperature during the operation, and the difference. The first remaining capacity specifying unit calculates a discharge amount of the secondary battery during operation of the vehicle measured by the discharge amount measurement unit, as a full charge amount at a predetermined charge end voltage value of the secondary battery. The battery control device according to any one of claims 1 to 5, wherein a remaining capacity of the secondary battery during operation of the vehicle is specified by subtracting from the battery. A charge amount measuring unit that measures the charge amount of the secondary battery when the secondary battery is charged until the voltage value of the secondary battery reaches a predetermined charge end voltage value from the discharge end voltage value When,
A full charge amount specifying unit for specifying the full charge amount based on the charge amount measured by the charge amount measuring unit;
The battery control device according to claim 6, wherein the first remaining capacity specifying unit specifies the remaining capacity by subtracting the discharge amount from the full charge amount specified by the full charge amount specifying unit. The battery control apparatus according to claim 7, further comprising a transmission unit that transmits data indicating the difference to a server that collects information about the secondary battery. The battery control device according to any one of claims 1 to 8, wherein the discharge control unit discharges the secondary battery after a predetermined period has elapsed after the operation of the vehicle is stopped. A connection control unit that electrically connects a secondary battery mounted on a vehicle and a load device that operates by receiving power supplied from the secondary battery during operation of the vehicle while the operation of the vehicle is stopped. When,
After the secondary battery and the load device are electrically connected by the connection control unit, the voltage value for acquiring the voltage value of the secondary battery at two different timings as the first voltage value and the second voltage value An acquisition unit;
A battery control apparatus comprising: a deterioration state specifying unit that specifies a deterioration state of the secondary battery based on the first voltage value and the second voltage value. A correlation holding unit that holds a correlation between the first voltage value, the second voltage value, and the deterioration state of the secondary battery;
The previous period deterioration state specifying unit specifies the deterioration state of the secondary battery corresponding to the first voltage value and the second voltage value acquired by the voltage value acquisition unit based on the correlation. The battery control apparatus described. The load device is a motor that is a drive source of the vehicle,
The battery control device according to claim 10 or 11, wherein the connection control unit electrically connects the secondary battery and the motor, and supplies a current to an excitation coil included in the motor. 13. The transmitter according to claim 10, further comprising: a transmission unit configured to transmit information indicating a deterioration state of the secondary battery specified by the deterioration state specifying unit to a server that collects information related to the secondary battery. The battery control device described in 1. The battery control device according to any one of claims 1 to 13,
A vehicle comprising the secondary battery.

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