JP2002340996A - Battery capacity judging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To judge battery capacity accurately, regarding a battery capacity judging device. SOLUTION: A current sensor is arranged between a battery and an M/G which sensor outputs a signal corresponding to a current flowing in a part between the battery and the M/G. A correction A is calculated by referring a map which is determined previously on the basis of a battery temperature T and the degree of deterioration J. A battery current I detected on the basis of an output signal of the current sensor is multiplied by the coefficient A. The capacity SOC of the battery is judged on the basis of an integrated value obtained by integrating the product value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a battery capacity judging device, and more particularly to a battery capacity judging device for judging the capacity of a battery based on an integrated value of charging / discharging current flowing through the battery.

[0002]

2. Description of the Related Art Conventionally, a state of charge (capacity) of a battery has been known.
Is known based on the integrated value of the charge / discharge current. When charging and discharging are performed between the battery and the electric device, a charging current or a discharging current flows during the charging and discharging. Therefore,
If the charge / discharge current accompanying the charge / discharge is integrated after the battery capacity is determined, the subsequent battery capacity can be determined.

[0003]

However, the charge acceptability of a battery varies according to the temperature and capacity of the battery, and also varies with the state of deterioration of the battery. Therefore, even if the same current flows, the current stored in the battery as energy is not constant. Also, due to the temperature characteristics of the sensor that detects the current, for example, when starting the vehicle, it is necessary to pass an excessive current from the battery to the electric device, but the current flows outside the allowable detection range of the sensor. As a result, an error may occur between the current value based on the output signal and the actual current value. Even if such a situation occurs, if the battery current detected based on the output signal of the sensor is integrated as it is, it is not possible to determine an accurate battery capacity.

[0004] The present invention has been made in view of the above points, and has as its object to provide a battery capacity determination device capable of accurately determining the battery capacity.

[0005]

The above object is achieved by the present invention.
A charge / discharge current detecting means for detecting a charge / discharge current flowing through the battery; a capacity determining means for determining a capacity of the battery based on an integrated value of the charge / discharge current detected by the charge / discharge current detecting means. A battery capacity determination device comprising: a current correction unit configured to correct a charge / discharge current detected by the charge / discharge current detection unit according to at least one of a battery temperature and a degree of deterioration of the battery; The determining means determines the battery capacity based on the integrated value of the charge / discharge current corrected by the current correcting means, and is achieved by a battery capacity determining apparatus.

In the present invention, the charging / discharging current detected by the charging / discharging current detecting means is corrected according to at least one of the battery temperature and the degree of deterioration of the battery. Then, the battery capacity is determined based on the integrated value of the corrected charge / discharge current. Therefore, according to the present invention, even when at least one of the battery temperature and the deterioration degree of the battery fluctuates, the charge / discharge current corresponding to the fluctuation is integrated for the determination of the battery capacity.
The battery capacity can be accurately determined.

[0007] The above object is as described in claim 2.
A battery capacity comprising: a charge / discharge current detection means for detecting a charge / discharge current flowing through a battery; and a capacity determination means for determining a capacity of the battery based on an integrated value of the charge / discharge current detected by the charge / discharge current detection means. In the determining device, the capacity determining means may be configured such that the charge / discharge current detected by the charge / discharge current detecting means is equal to or greater than a predetermined current value in a situation where the difference between the determined battery capacity and the target capacity is equal to or less than a predetermined difference. In this case, the battery capacity determination device corrects the determined battery capacity.

In the present invention, when the difference between the battery capacity and the target capacity determined based on the integrated value of the charge / discharge current is equal to or smaller than a predetermined difference, and the charge / discharge current is equal to or larger than the predetermined current value, The battery capacity determined as described above is corrected. Generally, as the actual capacity of the battery is closer to the target capacity, the charging / discharging current becomes more difficult to flow. Therefore, the current value of the charging / discharging current is high even though the battery capacity determined by the capacity determining means approaches the target capacity. In this case, it can be determined that the determined battery capacity deviates greatly from the actual capacity. Therefore, according to the present invention, when the charge / discharge current is high when the battery capacity approaches the target capacity, the battery capacity is corrected, so that the capacity of the battery can be accurately determined.

In this case, as set forth in claim 3, in the battery capacity judging device according to claim 2, the capacity judging means operates under a situation where the difference between the judged battery capacity and the target capacity is equal to or smaller than a predetermined difference. When the state in which the charge / discharge current detected by the charge / discharge current detection means is equal to or more than a predetermined current value continues for a predetermined time, the determined battery capacity is increased or decreased by a predetermined capacity value. Thus, the deviation of the battery capacity from the actual capacity can be eliminated.

By the way, the battery capacity and charge / discharge current are as follows:
It fluctuates according to the temperature and the degree of deterioration of the battery. For this reason, if the predetermined difference, the predetermined current value, the predetermined time, and the predetermined capacity value are maintained at constant values, it is impossible to accurately determine the battery capacity.

Therefore, as set forth in claim 4, in the battery capacity judging device according to claim 2 or 3, at least one of the predetermined difference, the predetermined current value, the predetermined time, and the predetermined capacity value. By providing a parameter correction unit that corrects the parameter according to at least one of the battery temperature and the degree of deterioration of the battery,
The accuracy of battery capacity determination can be improved.

Further, the above object is achieved by a charging / discharging current detecting means for detecting a charging / discharging current flowing through a battery, and an integrated value of the charging / discharging current detected by the charging / discharging current detecting means. And a capacity determining means for determining the capacity of the battery based on the charge and discharge currents when the charge current detected by the charge and discharge current detection means is equal to or less than a predetermined value. This is achieved by a battery capacity determination device, which is provided with an integration prohibition unit for prohibiting the operation.

In the present invention, when the charging current detected by the charging / discharging current detecting means is equal to or less than a predetermined value, the integration of the charging / discharging current is prohibited. When the charging current is small, it can be determined that the battery capacity has approached the desired capacity.However, if the state where the charging current is small continues, for example, although the current is used for heat loss due to the internal resistance of the battery, Increasing the integrated amount may affect the determination of the battery capacity. Therefore, according to the present invention, when the charging current is small, the integration is prohibited, so that erroneous determination of the battery capacity can be prevented.

Incidentally, the charge / discharge current varies depending on the temperature of the battery and the degree of deterioration. For this reason, if the above-mentioned predetermined value is maintained at a constant value, it is impossible to properly prevent erroneous determination of the battery capacity.

Therefore, as set forth in claim 6, in the battery capacity judging device according to claim 5, there is provided a predetermined value correcting means for correcting the predetermined value according to at least one of a battery temperature and a degree of battery deterioration. In this case, the accuracy of battery capacity determination can be improved.

[0016]

FIG. 1 is a block diagram of a system equipped with a battery capacity judging device according to a first embodiment of the present invention. The system of this embodiment includes a battery 10 functioning as a vehicle power supply. The battery 10 is composed of a plurality of battery cells connected in series, and is, for example, a lead-acid battery having an output voltage of about 36V.

A motor generator (hereinafter, referred to as M / G) 14 is connected to the battery 10 via an inverter 12. The inverter 12 has a built-in motor power transistor, and converts the DC power of the battery 10 into the AC power of the M / G 14 according to the switching operation of the motor power transistor. M / G14
When the power transistor for the motor is in the ON state, the power is supplied from the battery 10 to drive the battery 10 as a power source and generate a predetermined torque for rotating the wheels. That is, the battery 10 supplies power to the M / G 14 when the motor power transistor of the inverter 12 is on.

The M / G 14 functions as a generator for converting kinetic energy of the vehicle into electric energy during regenerative braking of the vehicle. The inverter 12 also has a built-in power transistor for a generator, and converts the AC power generated by the M / G 14 into the DC power of the battery 10 according to the switching operation of the power transistor for the generator. That is, in a situation where the power transistor for the generator of the inverter 12 is in the ON state, the battery 10 is driven by the M / G 16 by the regenerative braking of the vehicle.
Is supplied with power by being generated, and is charged.

The inverter 12 is connected to an electronic control unit (hereinafter referred to as an ECU) 16 constituted by a microcomputer. When the ECU 16 determines that power supply from the battery 10 to the M / G 14 is necessary, the ECU 16 controls the inverter 12 so that the battery 10 is discharged.
A command signal is supplied to the motor power transistor. When it is determined that power supply from the M / G 14 to the battery 10 is necessary, a command signal is supplied to the power transistor for generator so that the battery 10 is charged.

A voltage sensor 20 disposed between the positive and negative terminals of the battery 10 is connected to the ECU 16. Voltage sensor 20 outputs a signal corresponding to a voltage between terminals of battery 10 (hereinafter, referred to as battery voltage V). The output signal of the voltage sensor 20 is supplied to the ECU 16. EC
U16 detects the battery voltage V of the battery 10 based on the output signal of the voltage sensor 20.

A current sensor 22 disposed between the battery 10 and the inverter 12 is connected to the ECU 16. The current sensor 22 outputs a signal corresponding to a current flowing between the battery 10 and the inverter 12 (hereinafter, referred to as a battery current I). The output signal of the current sensor 22 is supplied to the ECU 12. The ECU 16 detects a battery current I flowing through the battery 10 based on an output signal of the current sensor 22. In this example,
The battery current I has a negative value when flowing from the battery 10 to the M / G 14, and has a positive value when flowing from the M / G 14 to the battery 10.

The ECU 16 is further connected to a temperature sensor 24 built in the battery 10. Temperature sensor 24 outputs a signal corresponding to the internal temperature of battery 10 (hereinafter, referred to as battery temperature T). The output signal of the temperature sensor 24 is supplied to the ECU 16. ECU16
Is based on the output signal of the temperature sensor 24.
Is detected.

In general, there is a correlation between the open-circuit voltage between the terminals of the battery 10 and its state of charge (hereinafter referred to as battery capacity SOC). Therefore, in the present embodiment, the ECU 12
At the time of no load when G14 is not operated, the battery capacity S is determined by referring to a predetermined correlation between the open-circuit voltage and the battery capacity based on the detected battery voltage V.
Determine OC. For example, when the battery 10 is fully charged, the battery capacity SOC is determined to be 100%, and when the charge amount of the battery 10 is zero, the battery capacity SOC is determined to be 0%. Hereinafter, ECU
The battery capacity SOC determined by 16 is referred to as an estimated battery capacity SOC.

When charging / discharging is performed between the battery 10 and the M / G 14, and the M / G 14 is activated, a charging current or a discharging current flows during the operation. Therefore, in the present embodiment, after the M / G 14 is activated, the ECU 16 calculates the integrated value of the charging / discharging current (battery current I) of the battery 10 based on the estimated battery capacity SOC determined when there is no load. The battery capacity SOC is calculated based on. According to such a method, it is possible to determine the capacity of the battery 10 even when the battery 10 is charging and discharging.

However, if the state of detecting the battery capacity SOC based on the integrated value of the charge / discharge current of the battery 10 continues for a long period of time, the error of the integrated value of the charge / discharge current increases. For example, the charge acceptability of the battery 10 varies according to the battery temperature T and the actual capacity of the battery 10 and also varies according to the deterioration state of the battery 10. Specifically, the battery 10 is more likely to be charged and discharged as the battery temperature T is higher, and is more difficult to charge and discharge as the battery 10 deteriorates. For this reason, even if the same current flows through the battery 10, the current stored in the battery 10 as energy is not constant. The current sensor 22
Has a temperature characteristic, an error may occur between the current value of the actually flowing current and the current value based on the output signal of the current sensor 22. Therefore, if the battery current I detected using the current sensor 22 is integrated without considering the deterioration state of the battery 10 or the battery temperature T, the capacity actually stored in the battery 10 is accurately determined. You will not be able to do it.

Therefore, in this embodiment, the battery 1
The value of the battery current I detected based on the output signal of the current sensor 22 is corrected in consideration of the deterioration state of 0 and the battery temperature T. Specifically, a correction coefficient for correcting the battery current I is calculated based on the deterioration state of the battery 10 and the battery temperature T by referring to a map which is experimentally determined in advance. 22
The value obtained by multiplying the battery current I detected based on the output signal of the battery 10 is grasped as the current by charging and discharging the battery 10. Then, the battery capacity SOC of the battery 10 is determined based on the corrected integrated value of the current.

In such a configuration, the battery capacity SO depends on the battery temperature T and the state of deterioration of the battery 10.
The magnitude of the current used for the determination of C is changed. Therefore, according to the battery capacity determination device of the present embodiment, the integration is performed using the current value calculated in consideration of the battery temperature T and the acceptability of the battery 10 and the sensor error which fluctuate according to the deterioration state of the battery 10. Therefore, it is possible to accurately determine the battery capacity SOC.

The state of deterioration of the battery 10 can be determined based on the magnitude of the internal resistance of the battery 10. That is, when the internal resistance of the battery 10 is large, the heat loss is large, and it can be determined that the battery 10 is deteriorated. On the other hand, when the internal resistance of the battery 10 is small, the heat loss is small, and it can be determined that the deterioration of the battery 10 has not progressed. Therefore, in the present embodiment, first, at a certain point (for example, at idle stop and M / G
14 is stored, the battery voltage V and the battery current I at different points in time (for example, when the vehicle internal combustion engine is started after an idle stop) are stored. V and the relationship between both battery currents I, the battery current I
, The slope of the battery voltage V is calculated, and the slope is grasped as the internal resistance of the battery 10. The degree of deterioration J of the battery 10 is determined based on the magnitude of the internal resistance.
(For example, one of three stages of large deterioration, medium deterioration, and small deterioration).

The features of this embodiment will be described below with reference to FIGS.

FIG. 2 is a flowchart showing an example of a control routine executed by the ECU 16 in this embodiment to realize the above-described functions. The routine shown in FIG. 2 is a routine started every predetermined time. When the routine shown in FIG. 2 is started, first, the process of step 100 is executed.

In step 100, the battery current I is detected based on the output signal of the current sensor 22, the battery temperature T is detected based on the output signal of the temperature sensor 24, and the relationship between the battery voltage V and the battery current I is determined. The process of detecting the degree of deterioration J of the battery 10 according to a predetermined map is executed based on the internal resistance grasped as the gradient of the battery voltage V with respect to the battery current I calculated from the two points respectively indicating the following.

In step 102, the above-mentioned step 100
Is performed based on the battery temperature T and the degree of deterioration J detected in step (a) to calculate a correction coefficient A for correcting the battery current I detected using the current sensor 22.

FIGS. 3 and 4 show maps used for calculating the correction coefficient A in this embodiment. FIG. 3 shows a map when the current flows from the M / G 14 to the battery 10, that is, a map for charging the battery 10, and FIG. 4 shows a case where a current flows from the battery 10 to the M / G 14, Each map for discharging the battery 10 is shown. At the time of charging the battery, as shown in FIG. 3, the correction coefficient A becomes smaller as the battery temperature T becomes higher than the normal temperature (+ 20 ° C.), becomes lower as the battery temperature T becomes lower than the normal temperature, and the deterioration of the battery 10 decreases. It gets smaller as it progresses. Further, at the time of battery discharge, as shown in FIG. 4, the correction coefficient A increases as the battery temperature T becomes higher than the normal temperature, increases as the battery temperature T becomes lower than the normal temperature, and the deterioration of the battery 10 progresses. It becomes bigger.

In step 102, the correction coefficient A is calculated based on the battery temperature T and the degree of deterioration J by referring to the map shown in FIG. 3 or FIG. When the detected battery temperature T or the degree of deterioration J is located in the middle of data stored as a map in the ECU 16, the correction coefficient A is calculated by, for example, linear interpolation.

In step 104, the value obtained as a result of multiplying the battery current I detected by the current sensor 22 by the correction coefficient A calculated in step 102 has actually contributed to the charging and discharging of the battery 10. process is performed to charge and discharge current I _1. Then, in step 106,
The process of determining the battery capacity SOC is performed by integrating the charge / discharge current I ₁ calculated in step 104. When the process of step 106 ends, the current routine ends.

According to the routine shown in FIG. 2, the battery current I detected based on the output signal of the current sensor 22 is not integrated as it is, but the acceptability that varies with the temperature and the deterioration state of the battery 10. The battery capacity SOC can be determined by integrating the current values corrected in consideration of the sensor error and the sensor error. Therefore, according to the battery capacity determination device of the present embodiment, it is possible to accurately determine the capacity of the battery 10 even when the temperature or the deterioration state of the battery 10 fluctuates.

When the actual capacity of the battery 10 is deviated from the estimated battery capacity SOC recognized by the system and increases, even if the power is recovered to the battery 10 by regenerative braking, a large amount of power is actually recovered. And the fuel efficiency of the vehicle may not be obtained.
Further, when the actual capacity is deviated from the estimated battery capacity SOC recognized by the system and becomes small, even if the battery 10 tries to supply power to the M / G 14, the battery 10 actually drives the M / G 14. It may not be possible to supply the required power. On the other hand, according to the system of the present embodiment, the capacity of the battery 10 can be properly managed, so that the fuel efficiency of the vehicle due to regenerative braking can be sufficiently exhibited. It is possible to reliably drive the M / G 14 by the discharge of the M / G 14.

In the first embodiment, the ECU is used.
16 detects the battery current I based on the output signal of the current sensor 22, so that the "charge / discharge current detecting means" recited in the claims performs the process of step 104 in the routine shown in FIG. The “current correction means” described in the claims by executing the processing, the “capacity determination means” described in the claims is realized by executing the processing in step 106.

By the way, in the first embodiment,
Although the battery temperature T is detected using the temperature sensor 20 built in the battery 10, the present invention is not limited to this, and the temperature sensor disposed around the battery 10 may be used. Is also good. Further, in the above-described first embodiment, the deterioration state of the battery 10 is grasped from the internal resistance of the battery 10. However, the deterioration state is grasped by using other parameters such as the frequency of use and the date of use. Is also good.

Further, in the above-described first embodiment, the present invention is applied to a system using a lead-acid battery as the battery 10. However, the first embodiment is applied to a system using another storage battery such as a nickel-metal hydride battery instead of the lead-acid battery. It is also possible to apply.

Next, a second embodiment of the present invention will be described with reference to FIGS.

The system of this embodiment is the same as the system shown in FIG. That is, in the present embodiment, the battery capacity SOC is determined based on the integrated value of the charge / discharge current of the battery 10.

In order to charge and discharge the battery 10 in a well-balanced manner, it is appropriate to control the battery 10 to a desired capacity (hereinafter, referred to as a target capacity). In general, the actual capacity of the battery 10 is correlated with the battery open circuit voltage. Therefore, in this embodiment, as a method of controlling the battery 10 to the target capacity, the battery 10 is charged and discharged at a battery open-circuit voltage (hereinafter, referred to as a target battery voltage) corresponding to the target capacity. That is, in the present embodiment, the ECU 16 stores a map indicating the relationship between the target capacity and the target battery voltage in advance, and calculates the target battery voltage corresponding to the set target capacity (for example, 75%). . Then, the inverter 12 is driven at a duty ratio at which the calculated target battery voltage is realized.

When the inverter 12 is driven at a duty ratio corresponding to the target battery voltage corresponding to the target capacity, the battery 10 repeats the charge state and the charge stop state at the duty ratio, or switches between the charge state and the discharge state. The discharge stop state is repeated. In this case, the terminal voltage V of the battery 10 changes toward the target battery voltage, and the capacity of the battery 10 changes toward the target capacity. Therefore, according to the present embodiment, it is possible to accurately maintain the capacity of the battery 10 at a desired target capacity.

In the above-described method, when controlling the capacity of the battery 10 to the target capacity, the ECU 16
Need not know the actual capacity of the battery 10. Therefore, in the process where the capacity of the battery 10 is controlled to the target capacity, even when the estimated battery capacity SOC determined by the ECU 16 approaches the target capacity, a large discharge current flows from the battery 10 or the battery 10 When a large charging current flows, the capacity of the battery 10 actually deviates greatly from the target capacity, and the ECU 10
It can be determined that the estimated battery capacity SOC recognized by 16 deviates from the actual capacity.

Therefore, in this embodiment, the ECU 16
If the battery current I based on the output signal of the current sensor 22 shows a large value despite that it is determined that the estimated battery capacity SOC to be recognized approaches the target capacity, the estimated battery capacity SOC recognized by the ECU 16 Is deviated from the actual capacity (hereinafter referred to as the actual capacity), and the battery capacity SOC is corrected.

FIG. 5 is a time chart for explaining the correction of the estimated battery capacity SOC recognized by the ECU 16 in this embodiment. In FIG. 5, the target capacity is indicated by a dashed line, the estimated battery capacity SOC is indicated by a broken line, and the actual capacity is indicated by a solid line. In this embodiment,
The ECU 16 calculates the estimated battery capacity SO as shown in FIG.
Under the situation where C is determined to have approached the target capacity, the estimated battery capacity SOC is added by a predetermined capacity each time the state where the battery current I shows a large value on the discharging side continues for a predetermined time (the upper half in FIG. reference). Each time the state where the battery current I shows a large value on the charging side continues for a predetermined time T, the estimated battery capacity SOC is subtracted by a predetermined capacity (see the lower half in FIG. 5).

Then, as a result of repeating such processing,
When the battery current I indicates a small value, it can be determined that the actual capacity of the battery 10 has approached the target capacity, and it can be determined that the estimated battery capacity SOC substantially matches the actual capacity. Cancel the correction of. Therefore, according to the system of the present embodiment, the capacity of the battery 10 can be accurately recognized by the ECU 16, and the capacity of the battery 10 can be accurately determined.

FIG. 6 is a flowchart showing an example of a control routine executed by the ECU 16 in this embodiment to realize the above-described functions. The routine shown in FIG. 6 is a routine that is started each time the processing is completed. When the routine shown in FIG. 6 is started, first, the process of step 120 is executed.

In step 120, it is determined whether or not the absolute value of the difference between the estimated battery capacity SOC recognized by the ECU 16 and the target capacity is equal to or smaller than a predetermined value α. Note that the predetermined value α
Is the maximum capacity difference when it can be determined that the estimated battery capacity SOC recognized by the ECU 16 substantially matches the target capacity. The process of step 120 is repeatedly executed until it is determined that the above condition is satisfied. As a result, | S
If it is determined that OC−target capacity | ≦ α is satisfied,
Next, the process of step 122 is performed.

[0051] At step 122, the absolute value of the battery current I detected based on the output signal of the current sensor 22 is equal to or less than a predetermined current value I ₀ is determined. The predetermined current value I ₀ is a minimum current value that can be determined to be flowing as the capacity of the battery 10 changes. | I | ≧ I
_{If 0} is not established, it can be determined that the battery current I has decreased because the actual capacity of the battery 10 has also approached the target capacity, and it can be determined that the estimated battery capacity SOC has not significantly deviated from the actual capacity of the battery 10. In this case, it is not necessary to correct the estimated battery capacity SOC recognized by the ECU 16. Therefore, | I | if ≧ I ₀ is determined not satisfied, the present routine is ended.

On the other hand, when | I | ≧ I ₀ holds, E
Even though the estimated battery capacity SOC recognized by the CU 16 has approached the target capacity, the actual capacity of the battery 10 has not approached the target capacity. Therefore, it can be determined that the battery current I has increased. It can be determined that the actual capacity of the battery 10 is greatly deviated.
In this case, it is necessary to correct the estimated battery capacity SOC recognized by the ECU 16. Therefore, if it is determined that | I | ≧ I ₀ holds, the process of step 124 is executed next.

In step 124, the timer counter CN
It is determined whether or not T has reached the predetermined value CNT0.
Note that the timer counter CNT is a counter for counting the duration time in which the condition of step 122 is satisfied. The predetermined value CNT0 is a minimum time in which it can be determined that noise in the output signal of the current sensor 22 does not continue. As a result, when it is determined that CNT ≧ CNT0 is not satisfied, the process of step 122 is repeatedly executed. On the other hand, if it is determined that CNT ≧ CNT0 holds, the process of step 126 is executed next.

In step 126, a value obtained by adding or subtracting a predetermined value β to or from the estimated battery capacity SOC recognized by the ECU 16 is used as a new estimated battery capacity S recognized by the ECU 16.
The process of setting to OC is performed. The predetermined value β is a correction amount for correcting the estimated battery capacity SOC at one time, and is set to, for example, 1%. Whether to add or subtract the predetermined value β is determined according to the direction of the battery current I. That is, the predetermined value β is added when the battery current I flows from the battery 10 to the M / G 14 and indicates a negative value.
The current flows from the battery 14 to the battery 10, and is subtracted when a positive value is indicated. After the processing of step 126 is executed, the ECU 16 thereafter sets the new battery capacity SO
C will be grasped as the capacity of the battery 10. When the process of step 126 is completed,
Step 2 is repeatedly executed.

According to the routine shown in FIG. 6, when a large battery current I flows in a situation where it is determined that the recognized estimated battery capacity SOC has approached the target capacity, the estimated battery capacity SOC is corrected. be able to. Therefore, when the estimated battery capacity SOC recognized by the ECU 16 is shifted from the actual capacity of the battery 10, the estimated battery capacity SOC can be changed toward the actual capacity.

It is determined that the larger the difference between the estimated battery capacity SOC recognized by the ECU 16 and the actual capacity of the battery 10 is, the more the estimated battery capacity SOC approaches the target capacity. , It takes a lot of time to reach, and the period during which the battery current I shows a large value becomes longer. On the other hand, the estimated battery capacity S
If the difference between the OC and the actual capacity is small, it does not take much time for the actual capacity of the battery 10 to reach the target capacity after it is determined that the estimated battery capacity SOC has approached the target capacity. The period when I is large is short.

In the present embodiment, the correction of the estimated battery capacity SOC recognized by the ECU 16 is performed stepwise according to the duration of the state where the battery current I shows a large value. It will be resolved step by step. At this time, as the state where the battery current I shows a large value continues for a long period of time, the estimated battery capacity SOC is corrected to be larger. For this reason, according to the present embodiment, it is possible to accurately determine the capacity of the battery 10 irrespective of how much the estimated battery capacity SOC deviates from the actual capacity. Therefore, also in the system of the present embodiment, since the capacity of the battery 10 can be properly managed, the fuel efficiency of the vehicle due to the regenerative braking can be sufficiently exhibited.
It is possible to reliably drive the M / G 14 by discharging the battery 10.

The higher the battery temperature T, the easier the battery 10 is charged and discharged, and the lower the battery temperature T, the more difficult it is to charge and discharge. In addition, while charging and discharging are easy in the initial stage of manufacturing, charging and discharging become difficult as deterioration proceeds. That is, the charging / discharging current contributing to the charging / discharging of the battery 10 varies according to the battery temperature T and the degree of deterioration J even when the battery current I based on the output signal of the current sensor 22 is the same. The capacity of 10 also varies.
Therefore, assuming that the above-mentioned predetermined value α, predetermined current value I ₀ , predetermined value CNT0, and predetermined value β are all maintained at constant values, it is possible to accurately determine the capacity of battery 10. become unable.

Therefore, in the present embodiment, the determination is made based on the battery temperature T detected based on the output signal of the temperature sensor 24 and the magnitude of the internal resistance of the battery 10 obtained from the battery voltage V and the battery current I. The above-described predetermined value α, the predetermined current value I ₀ , the predetermined value CNT0, or the predetermined value β may be corrected based on at least one of the deteriorated states of the battery 10. In this case, according to the temperature or the deterioration state of the battery 10, the EC
Since the correction process of the estimated battery capacity SOC recognized by U16 is performed, the accuracy of the determination of the capacity of the battery 10 can be improved.

At this time, the ECU 16 corrects the predetermined value α, the predetermined current value I ₀ , the predetermined value CNT0, or the predetermined value β according to at least one of the battery temperature T and the degree of deterioration J, so that the claimed invention is not limited to the above. "Parameter correction means" described in the range is realized.

In the second embodiment, the predetermined value α is set to the “predetermined difference” described in the claims, and the predetermined current value I ₀ is set to the “predetermined current value” set forth in the claims. "
The predetermined value CNT0 corresponds to the “predetermined time” described in the claims, and the predetermined value β corresponds to the “predetermined capacity value” described in the claims.

Next, a third embodiment of the present invention will be described with reference to FIG.

The system of this embodiment is the same system as the system shown in FIG. That is, in the present embodiment, the battery capacity SOC is determined based on the integrated value of the charge / discharge current of the battery 10.

By the way, even when the actual capacity approaches the target capacity when charging the battery 10, the M / G 14
Slight charging current flows to the This charging current does not contribute to the charging of the battery 10 but is consumed as heat loss due to the internal resistance of the battery 10. However, the battery capacity S is determined based on the integrated value of the battery current I detected using the current sensor 22 as in the present embodiment.
In the configuration in which the OC is determined, even though the actual capacity is maintained at the target capacity, the flow of the small charging current continues, so that the integrated value increases, and E
A situation occurs that affects the estimated battery capacity SOC recognized by the CU 16. Therefore, after the battery current I detected based on the output signal of the current sensor 22 at the time of charging the battery 10 becomes small to some extent, it is appropriate to prohibit the integration of the battery current and prevent the battery capacity SOC from being erroneously determined. It is.

Therefore, the system of this embodiment is characterized in that when the battery current I detected by the current sensor 22 at the time of charging the battery drops below a predetermined value, the integration of the charging / discharging current is prohibited. ing. According to this configuration, the battery current I that does not contribute to the charging of the battery 10 and is consumed as heat loss due to the internal resistance is not added to the integrated value for determining the battery capacity SOC. Erroneous determination can be prevented.

FIG. 7 is a flowchart showing an example of a control routine executed by the ECU 16 in the present embodiment to realize the above-described functions. The routine shown in FIG. 7 is a routine that is repeatedly started at predetermined time intervals. When the routine shown in FIG. 7 is started, first, the process of step 140 is executed.

In step 140, the magnitude of the current flowing from M / G 14 to battery 10 is determined by a predetermined threshold value I
It is determined whether or not it is equal to or less than _SH . In this embodiment,
Since the battery current I based on the output signal of the current sensor 22 has a positive value at the time of charging, specifically, the battery current I detected based on the current sensor 22 is equal to or less than a predetermined threshold value I _SH , and , "0" or more. Note that the predetermined threshold value I _SH is consumed as heat loss due to the internal resistance of the battery 10 during charging,
This is the maximum current value determined not to contribute to the charging of the battery 10.

As a result, when 0 ≦ I ≦ I _SH does not hold, it is determined that a large charging current is flowing from the M / G 14 to the battery 10 or a discharging current is flowing from the battery 10 to the M / G 14. it can. In this case, it is appropriate to integrate the battery current I in order to determine the capacity of the battery 10. Therefore, when such a determination is made, the process of step 142 is executed next. on the other hand,
When 0 ≦ I ≦ I _SH holds, a small current flows from the M / G 14 to the battery 10, and the current is consumed as heat loss due to the internal resistance of the battery 10.
It does not contribute to the charging of the battery. In this case, it is not appropriate to integrate the battery current I to determine the capacity of the battery 10. Therefore, when such a determination is made, the process of step 144 is executed next.

In step 142, a process for permitting the integration of the battery current I is executed. When the process of step 142 is performed, the battery current I detected based on the output signal of the current sensor 22 is added to the integrated value for determining the capacity of the battery 10 thereafter. When the process of step 142 ends, the current routine ends.

On the other hand, in step 144, a process for inhibiting the integration of the battery current I is executed. Step 14
After the process of No. 4, the battery current I is not added to the integrated value for determining the capacity of the battery 10 even if the battery current I is detected based on the output signal of the current sensor 22 thereafter. . When the process of step 144 ends, the current routine ends.

According to the routine shown in FIG. 7, the M / G
When the charging current from the battery 14 to the battery 10 is small, the current value can be prohibited from being added to the integrated value for determining the capacity of the battery 10. That is, in a situation where the actual current of the battery 10 substantially matches the target capacity, even if the current consumed as heat loss due to the internal resistance of the battery 10 continues to flow, the integration of the current value is prohibited. Is done. Therefore, according to the present embodiment, the estimated battery capacity SO determined by the ECU 16 due to the integration of the current value that does not contribute to the charging of the battery 10
C does not change, and erroneous determination of the capacity of the battery 10 can be prevented.

Therefore, also in the system of this embodiment,
Since the capacity of the battery 10 can be properly managed, the fuel efficiency of the vehicle due to the regenerative braking can be sufficiently exerted.
/ G14 can be reliably driven.

When the battery 10 is charged, the current that is consumed as heat loss due to the internal resistance of the battery 10 and does not contribute to the charging of the battery 10 fluctuates according to the temperature and the deterioration state of the battery 10. For this reason, if the above-mentioned predetermined threshold value I _SH is maintained at a constant value, a situation arises in which the integration of the battery current I is prohibited despite contributing to the charging of the battery 10.
Alternatively, a situation may occur in which the integration of the battery current I continues even though the battery 10 no longer contributes to the charging of the battery 10.

Therefore, in the present embodiment, the predetermined threshold value I _SH may be changed according to at least one of the battery temperature T and the deterioration degree J. In this case, an appropriate threshold value I _SH is set in accordance with the temperature or the state of deterioration of the battery 10, so that the integration of the battery current I can be permitted or prohibited at an appropriate time, and the capacity of the battery 10 Can be improved. At this time, the ECU 16 corrects the threshold value I _SH according to at least one of the battery temperature T and the degree of deterioration J, thereby realizing the “predetermined value correcting means” described in the claims.

In the third embodiment, the predetermined threshold value I _SH corresponds to the “predetermined value” described in the claims, and the ECU 16 executes the steps in the routine shown in FIG. By executing the process of 144, the “integration prohibition unit” described in the claims is realized.

As described above, according to the first aspect of the present invention, the battery capacity can be accurately determined in consideration of at least one of the temperature and the degree of deterioration of the battery.

According to the second aspect of the present invention, when the charge / discharge current is high when the battery capacity approaches the target capacity, the battery capacity is corrected, so that the battery capacity can be accurately determined. .

According to the third aspect of the invention, the deviation of the determined battery capacity from the actual capacity can be eliminated.

According to the fourth and sixth aspects of the present invention, it is possible to improve the accuracy of determining the battery capacity by considering at least one of the temperature and the degree of deterioration of the battery.

According to the fifth aspect of the present invention, when the charge / discharge current is low, the integration is prohibited, so that an erroneous determination of the battery capacity can be prevented.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a system equipped with a battery capacity determination device according to a first embodiment of the present invention.

FIG. 2 is a flowchart of an example of a control routine executed to determine a battery capacity in the embodiment.

FIG. 3 is a diagram showing a map used for calculating a correction coefficient in the present embodiment.

FIG. 4 is a diagram showing a map used for calculating a correction coefficient in the present embodiment.

FIG. 5 is an example time chart for explaining correction of a battery capacity in the second embodiment of the present invention.

FIG. 6 is a flowchart of an example of a control routine executed to determine a battery capacity in the embodiment.

FIG. 7 is a flowchart of an example of a control routine executed to determine whether to permit or prohibit integration of battery current for determining battery capacity in the present embodiment.

[Explanation of symbols]

 Reference Signs List 10 battery 16 electronic control unit (ECU) 22 current sensor 24 temperature sensor I battery current T battery temperature J deterioration degree SOC battery capacity

Continued on front page F term (reference) 2G016 CA03 CB06 CB11 CB12 CB21 CB22 CB31 CB32 CC01 CC03 CC04 CC07 CC10 CC13 CC21 CC23 CC27 CD02 CD04 CF06 5G003 AA07 BA01 DA07 EA05 FA06 GB06 GC05 5H030 AA06 AS20 FF22 FF42 PIPGPI PO17 PV09 PV23 QI04 QN02 SE04 SE06 TI02 TI06 TO05 TO12

Claims (6)

[Claims] A charge / discharge current detecting means for detecting a charge / discharge current flowing through the battery; a capacity determining means for determining a capacity of the battery based on an integrated value of the charge / discharge current detected by the charge / discharge current detecting means. And a current correction means for correcting the charge / discharge current detected by the charge / discharge current detection means according to at least one of a battery temperature and a degree of deterioration of the battery. A battery capacity determination device, wherein the determination means determines the capacity of the battery based on the integrated value of the charge / discharge current corrected by the current correction means. 2. A charge / discharge current detection means for detecting a charge / discharge current flowing through a battery, and a capacity determination means for determining a capacity of the battery based on an integrated value of the charge / discharge current detected by the charge / discharge current detection means. A battery capacity determination device comprising: a charge / discharge current detected by the charge / discharge current detection means in a situation where a difference between the determined battery capacity and the target capacity is equal to or less than a predetermined difference. A battery capacity determining device that corrects the determined battery capacity when is greater than or equal to a predetermined current value. 3. The battery capacity judging device according to claim 2, wherein the capacity judging means detects the charging / discharging current detecting means in a situation where a difference between the judged battery capacity and the target capacity is equal to or smaller than a predetermined difference. A battery capacity determination device, wherein the determined battery capacity is increased or decreased by a predetermined capacity value each time a state in which the determined charge / discharge current is equal to or more than a predetermined current value continues for a predetermined time. 4. The battery capacity judging device according to claim 2, wherein at least one parameter among the predetermined difference, the predetermined current value, the predetermined time, and the predetermined capacity value is set as a battery temperature and a battery capacity. A battery capacity determination device, comprising: a parameter correction unit that corrects according to at least one of the degrees of deterioration. 5. A charge / discharge current detecting means for detecting a charge / discharge current flowing through a battery, and a capacity determining means for determining a capacity of the battery based on an integrated value of the charge / discharge current detected by the charge / discharge current detecting means. A battery capacity determination device comprising: an accumulation prohibition unit for prohibiting the integration of the charge / discharge current when the charge current detected by the charge / discharge current detection unit is equal to or less than a predetermined value. Battery capacity determination device. 6. The battery capacity determination device according to claim 5, further comprising a predetermined value correction unit that corrects the predetermined value according to at least one of a battery temperature and a degree of deterioration of the battery. apparatus.