JP2003243045A - Method and device for calculating residual capacity - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform a correcting process for the residual capacity of a secondary battery when an engine is to be started. <P>SOLUTION: The residual capacity calculating device is composed of an ammeter 108 to sense the charge-discharge current of the secondary battery 104, a voltmeter 110 to sense the voltage of the battery 104, a condition sensor 106 for sensing the timing at which electric discharging from the battery 104 to the engine 100 is started, and a battery ECU 116 for calculating the residual capacity of the battery 104, wherein the battery ECU 116 corrects the residual capacity on the basis of the sensed current and voltage in such a way as corresponding to the sensed timing. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for calculating the state of charge of a secondary battery, and more particularly to a state of charge calculated by correcting the state of charge of the secondary battery based on the time when the secondary battery discharges to a load. Technology for improving the accuracy of.

[0002]

2. Description of the Related Art A secondary battery is used as a main power source or an auxiliary power source.
Used in automobiles, hybrid cars, electric carts, etc. The importance of secondary batteries is increasing due to the increasing awareness of environmental protection. Japanese Patent Laid-Open No. 11-174134 discloses
A device for grasping the state of a secondary battery, for example, the remaining capacity is disclosed.

The device disclosed in this publication has a remaining capacity detecting circuit for detecting the remaining capacity of a secondary battery, a region defining circuit for defining a current-voltage region, and a device sufficient for leaving the defined region. It includes a confirmation circuit for confirming whether charging or discharging has been performed, and a prohibition circuit for prohibiting the detection operation by the remaining capacity detection circuit until the confirmation by the confirmation circuit is completed.

This device corrects the remaining capacity according to whether the value of the remaining capacity is within the range of a predetermined area. That is, when the calculated remaining capacity is below the lower limit value (for example, 20%) or above the upper limit value (for example, 80%), the remaining capacity is corrected, and the corrected remaining capacity is corrected. The correction process is not executed again until the capacity leaves the predetermined area. as a result,
It is possible to prevent an error in the remaining capacity from occurring.

When the secondary battery is normally used, that is, when the secondary battery is used so as to be repeatedly charged and discharged, the calculated remaining capacity (hereinafter, referred to as a calculated value) and the actual remaining capacity. (Hereinafter, it is represented as an actual value.)

[0006]

However, when the secondary battery spontaneously discharges, its remaining capacity decreases. As a result, the actual value deviates from the calculated value. For example, the remaining capacity of a secondary battery of an automobile that has not been used for a long period of time decreases due to spontaneous discharge. The calculated value represents the last calculated remaining capacity. At this time, the calculated value deviates upward from the actual value. Also, when the secondary battery is replaced, a secondary battery different from the secondary battery for which the remaining capacity was finally calculated is used. As a result, the calculated value deviates from the actual remaining capacity.

When the calculation device disclosed in the above publication executes the calculation process of the remaining capacity when the secondary battery is naturally discharged, the value of the remaining capacity of the secondary battery displayed on the monitor or the like is calculated. It decreases until there is no difference between the actual value and the actual value.
The indication of the remaining capacity continues to show a decrease in the remaining capacity of the secondary battery, even though the secondary battery is being charged. Figure 7
FIG. 4 shows the transition of the calculated value and the actual value when the device disclosed in the above-mentioned publication executes the calculation processing of the remaining capacity.

The present invention has been made in order to solve the above-mentioned problems, and corrects the remaining capacity based on the time when the secondary battery is discharged to the load, and the remaining of the secondary battery with high accuracy is high. An object of the present invention is to provide a remaining capacity calculating device and a remaining capacity calculating method capable of calculating the capacity.

[0009]

A remaining capacity calculation device according to a first invention is a remaining capacity calculation device for calculating a remaining capacity of a secondary battery connected to a load, which is connected to the secondary battery, Current detection means for detecting the charging / discharging current of the secondary battery, voltage detection means connected to the secondary battery for detecting the voltage of the secondary battery, and discharge from the secondary battery to the load is started. Connected to the current detection means, the voltage detection means, and the detection means for detecting the time when the secondary battery is detected based on the detected current and the detected voltage. And a calculating unit for calculating the remaining capacity of.

According to the first aspect of the invention, the current detecting means detects the charging / discharging current of the secondary battery. The voltage detection means detects the terminal voltage of the secondary battery. The detection means detects the time when the discharge from the secondary battery to the load is started. When the current and voltage are detected, the calculation means calculates the remaining capacity before correction. When the time when the load is discharged is detected, the calculation means selects a parameter (for example, a correction gain map that gives a correction amount) used in the calculation process in accordance with the detected time, and calculates the correction amount. . The calculation means corrects the remaining capacity of the secondary battery based on the calculated correction amount. Thereby, the remaining capacity of the secondary battery is corrected according to the time when the secondary battery is discharged to the load. As a result, it is possible to provide a highly accurate remaining capacity calculation device that corrects the remaining capacity based on the time when the secondary battery is discharged to the load and can calculate the remaining capacity of the secondary battery with high accuracy.

In the state-of-charge calculating apparatus according to the second invention, in addition to the configuration of the first invention, the detecting means discharges the load based on either the detected current or the detected voltage. It includes means for detecting when it is started.

According to the second aspect of the invention, the detecting means is based on either the detected current or the detected voltage,
For example, the time when the discharge to the load is started is detected by detecting the change in the discharge current. Thereby, the remaining capacity of the secondary battery is corrected in accordance with the time detected based on either the current or the voltage. As a result, it is possible to provide a state-of-charge calculation device capable of correcting the state-of-charge based on the time when the secondary battery is discharged into the load and calculating the state-of-charge with high accuracy.

The remaining capacity calculating device according to a third aspect of the invention is, in addition to the configuration of the first aspect of the invention, information for storing information that realizes two or more methods for calculating the remaining capacity of a secondary battery. The calculation means further includes a storage means and a method selection means for selecting one method from the two or more stored methods corresponding to the detected time, and the calculation means includes the detected current and the detected current. Based on the selected voltage and the selected method
A means for calculating the remaining capacity of the secondary battery is included.

According to the third invention, the information storage means stores information (for example, a mathematical formula for calculating the remaining capacity) for realizing the method for calculating the remaining capacity of the secondary battery. The method selecting means selects one method from two or more stored methods, for example, a mathematical formula for calculating the remaining capacity, corresponding to the time detected by the detecting means. The calculating means calculates the remaining capacity of the secondary battery based on the detected voltage, the detected voltage and the selected method. As a result, the remaining capacity of the secondary battery corresponds to the detected time, and for example, when the detected time is when engine cranking starts, the time required for the remaining capacity calculation process is short. It is corrected by selecting the method. As a result, it is possible to provide a highly accurate remaining capacity calculation device that corrects the remaining capacity based on the time when the secondary battery is discharged to the load and can calculate the remaining capacity of the secondary battery with high accuracy.

In addition to the configuration of the first invention or the second invention, the remaining capacity calculation device according to the fourth invention stores two or more parameters calculated in advance based on the characteristic value of the secondary battery. Further comprising: a storage means for performing the operation, and a detection means and a selection means connected to the storage means for selecting one parameter from the two or more parameters stored corresponding to the detected time, The calculating means includes means for calculating the remaining capacity of the secondary battery based on the detected current, the detected voltage and the selected parameter.

According to the fourth aspect of the invention, the storage means calculates two or more parameters, which are calculated in advance, for example, based on the characteristic value of the secondary battery, for example, the relationship between the battery temperature and the estimated remaining capacity. The time constant that controls the time when the electromotive force converges is stored. The selection means selects one parameter from the stored two or more parameters corresponding to the detected time. The calculating means corrects the remaining capacity of the secondary battery based on the detected current, the detected voltage and the selected parameter. Thus, the remaining capacity of the secondary battery corresponds to the detected time, for example, when the detected time is when engine cranking starts, the time required for the calculated electromotive force to converge. It is corrected by using a shortening time constant. As a result, it is possible to provide a highly accurate remaining capacity calculation device that corrects the remaining capacity based on the time when the secondary battery is discharged to the load and can calculate the remaining capacity of the secondary battery with high accuracy.

A remaining capacity calculation device according to a fifth aspect of the invention is a device for calculating the remaining capacity of a secondary battery connected to a power source for driving a vehicle, and has the configuration according to any one of the first to fourth aspects. In addition, the detection means includes means for detecting when the power source begins to start.

According to the fifth invention, the detecting means detects the time when the power source, for example, the engine of the automobile, starts to start. The calculation means, based on the time of detection,
Correct the remaining capacity of the secondary battery. Thereby, the remaining capacity of the secondary battery is corrected corresponding to the time when the power source starts to start. As a result, it is possible to provide a highly accurate remaining capacity calculation device that corrects the remaining capacity based on the time when the secondary battery is discharged to the load and can calculate the remaining capacity of the secondary battery with high accuracy.

A remaining capacity calculating device according to a sixth aspect of the present invention is a device for calculating a remaining capacity of a secondary battery connected to a power source for driving a vehicle and auxiliary electric components of the vehicle, which is the first to fourth aspects. In addition to the structure of any one of the above aspects, the detecting means includes means for detecting a time when the use of the auxiliary electric component is started.

According to the sixth aspect of the present invention, the detecting means detects the time when the auxiliary electrical equipment, for example, the car audio device is started to be used. The calculating means corrects the remaining capacity of the secondary battery according to the detected time. Thereby, the remaining capacity of the secondary battery is corrected in accordance with the time when the use of the auxiliary electric component is started. As a result, it is possible to provide a highly accurate remaining capacity calculation device that corrects the remaining capacity based on the time when the secondary battery is discharged to the load and can calculate the remaining capacity of the secondary battery with high accuracy.

A remaining capacity calculating method according to a seventh aspect of the present invention is a remaining capacity calculating method for calculating a remaining capacity of a secondary battery connected to a load, and a current detecting step for detecting a charging / discharging current of the secondary battery. And a voltage detection step for detecting the voltage of the secondary battery, a detection step for detecting the time when the discharge from the secondary battery to the load is started, and a detected current and detection corresponding to the detected time. And a calculation step of calculating the remaining capacity of the secondary battery based on the determined voltage.

According to the seventh invention, the current detecting step detects the charging / discharging current of the secondary battery. The voltage detection step detects the terminal voltage of the secondary battery. The detection step detects the time when discharge from the secondary battery to the load is started. When the current and voltage are detected, the calculation step calculates the remaining capacity before correction. When the time when the load is discharged is detected, the calculation step selects a parameter (for example, a correction gain map that gives a correction amount) used in the calculation process in accordance with the detected time, and calculates the correction amount. . The calculation step corrects the remaining capacity of the secondary battery based on the calculated correction amount. Thereby, the remaining capacity of the secondary battery corresponds to the time when it is discharged to the load,
Will be corrected. As a result, it is possible to provide a highly accurate remaining capacity calculation method capable of correcting the remaining capacity based on the time when the secondary battery is discharged to the load and calculating the remaining capacity of the secondary battery with high accuracy.

In the remaining capacity calculating method according to the eighth invention, in addition to the configuration of the seventh invention, in the detecting step, the discharge to the load is performed based on either the detected current or the detected voltage. Detecting when to start.

According to the eighth aspect of the present invention, the detecting step detects the change in the discharge current based on either the detected current or the detected voltage.
Detect when the discharge to the load begins. The calculation step corrects the remaining capacity based on the detected time. Thereby, the remaining capacity of the secondary battery is corrected in accordance with the time detected based on either the current or the voltage. As a result, it is possible to provide a highly accurate remaining capacity calculation method capable of correcting the remaining capacity based on the time when the secondary battery is discharged to the load and calculating the remaining capacity of the secondary battery with high accuracy.

The remaining capacity calculating method according to the ninth invention is, in addition to the configuration of the seventh invention, an information preparing step for preparing information for realizing two or more methods for calculating the remaining capacity of the secondary battery. And a method selecting step of selecting one method from the prepared two or more methods according to the detected time, and the calculating step includes the detected current, the detected voltage and the selection. Based on the method
The step of calculating the remaining capacity of the secondary battery is included.

According to the ninth invention, the information preparing step prepares information (for example, a mathematical expression for calculating the remaining capacity) for realizing two or more methods for calculating the remaining capacity of the secondary battery. In the method selection step, one method is selected from the prepared two or more methods according to the detected time. The calculating step corrects the remaining capacity of the secondary battery based on the detected current, the detected voltage and the selected method. As a result, the remaining capacity of the secondary battery corresponds to the detected time, and for example, when the detected time is when engine cranking starts, the time required for the remaining capacity calculation process is short. It is corrected by selecting the method. As a result, it is possible to provide a highly accurate remaining capacity calculation method capable of correcting the remaining capacity based on the time when the secondary battery is discharged to the load and calculating the remaining capacity of the secondary battery with high accuracy.

The remaining capacity calculating method according to the tenth invention is as follows:
In addition to the configuration of the seventh invention or the eighth invention, a preparation step of preparing two or more parameters calculated in advance based on the characteristic value of the secondary battery, and a preparation step corresponding to the detected time And a selecting step of selecting one parameter from the two or more selected parameters, the calculating step based on the detected current, the detected voltage and the selected parameter, the remaining capacity of the secondary battery. Including the step of calculating

According to the tenth invention, the preparation step includes
Prepare two or more parameters calculated in advance based on the characteristic value of the secondary battery, for example, the relationship between the battery temperature and the estimated remaining capacity, for example, a time constant that controls the time for which the calculated electromotive force converges. To do. In the selection step, one parameter is selected from the prepared two or more parameters corresponding to the detected time. The calculating step corrects the remaining capacity of the secondary battery based on the detected current, the detected voltage and the selected parameter. Thus, the remaining capacity of the secondary battery corresponds to the detected time, for example, when the detected time is when engine cranking starts, the time required for the calculated electromotive force to converge. It is corrected by using a shortening time constant. As a result, it is possible to provide a highly accurate remaining capacity calculation method capable of correcting the remaining capacity based on the time when the secondary battery is discharged to the load and calculating the remaining capacity of the secondary battery with high accuracy.

The remaining capacity calculation method according to the eleventh invention is as follows:
In addition to the configuration of any one of the seventh to tenth inventions, a method of calculating the remaining capacity of a secondary battery connected to a power source for driving a vehicle, wherein the detecting step is connected to the secondary battery Detecting when the power source begins to start.

According to the eleventh invention, the detecting step comprises:
Detect when the power source, for example, the vehicle engine, begins to start. The calculating step corrects the remaining capacity of the secondary battery based on the detected time. This allows
The remaining capacity of the secondary battery is corrected according to the time when the power source starts to start. As a result, it is possible to provide a highly accurate remaining capacity calculation method capable of correcting the remaining capacity based on the time when the secondary battery is discharged to the load and calculating the remaining capacity of the secondary battery with high accuracy.

The remaining capacity calculating method according to the twelfth invention is as follows:
In addition to the configuration of any one of the seventh to tenth inventions, the detecting step includes a step of detecting a time when the use of the auxiliary electric component connected to the secondary battery is started.

According to the twelfth invention, the detecting step comprises:
Detecting when to start using auxiliary electrical equipment, such as a car audio device. The calculation step corrects the remaining capacity of the secondary battery in accordance with the detected time. Thereby, the remaining capacity of the secondary battery is corrected in accordance with the time when the use of the auxiliary electric component is started. As a result, it is possible to provide a highly accurate remaining capacity calculation method capable of correcting the remaining capacity based on the time when the secondary battery is discharged to the load and calculating the remaining capacity of the secondary battery with high accuracy.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same parts are designated by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

FIG. 1 shows a control block diagram of a vehicle including a remaining capacity calculating device according to an embodiment of the present invention. This vehicle includes an engine 100, an auxiliary electrical component 120, an ignition switch (hereinafter referred to as an I / G switch) 1
02, secondary battery 104, state detection sensor 106, ammeter 108, voltmeter 110, memory 112, I / F 114,
A battery ECU (Electronic Control Unit) 116, a monitor 118, and a temperature sensor 122 are included.

Engine 100 and auxiliary electrical components 120
Is connected to the secondary battery 104 via the I / G switch 102. The auxiliary electrical component 120 is, for example, a car audio device, a car air conditioner, or the like. Secondary battery 104
Is connected to the state detection sensor 106, the ammeter 108 and the voltmeter 110.

The state detection sensor 106 is the engine 100.
And the secondary battery 104. State detection sensor 1
06, ammeter 108, voltmeter 110 and temperature sensor 1
22 is a battery ECU via the interface 114
116 is connected. Memory 112 and monitor 118
Is connected to the battery ECU 116.

The state detection sensor 106 detects the position of the I / G switch 102 to detect when the engine 100 starts to start. This timing may be detected, for example, by a change in acceleration when the crankshaft starts or a change in current when the secondary battery 104 is discharged.

The ammeter 108 detects the discharging current from the secondary battery 104 and the charging current to the secondary battery 104.
The voltmeter 110 detects the terminal voltage of the secondary battery 104. The terminal voltage represents the voltage of the output terminal of the secondary battery 104. The temperature sensor 122 detects the temperature of the secondary battery 104.

The memory 112 stores a mathematical expression (hereinafter referred to as mathematical expression (1)) used for calculating the electromotive force V (1). The mathematical expression (1) is, for example, V (1) = (terminal voltage-polarization voltage-internal resistance voltage drop). V (1)
Is the electromotive force before the attenuation process described below. The terminal voltage is detected by the voltmeter 110. The polarization voltage and the internal resistance voltage drop are calculated by the battery ECU 116 based on the current detected by the ammeter 108.

The memory 112 stores a pre-specified electromotive force-remaining capacity map representing the relationship between the electromotive force of the secondary battery 104 and the estimated remaining capacity. The estimated remaining capacity is specified based on this map and the electromotive force. Memory 1
Reference numeral 12 stores a gain map used for calculating the remaining capacity of the secondary battery 104.

2 and 3 show gain maps stored in the memory 112. FIG. 2 shows the correction gain map M (2) used in the calculation process executed when the engine 100 does not start cranking. Figure 3
In addition, the correction gain map M used in the calculation process executed when the engine 100 starts cranking.
(1) is shown. The battery ECU 116 uses the temperature sensor 122.
The correction gain used to calculate the correction amount is specified based on the temperature of the secondary battery 104 detected by the.

The difference between FIG. 2 and FIG. 3 is the magnitude of the correction gain. The correction gain in FIG. 3 used when the engine 100 starts cranking is larger than the correction gain in FIG. As a result, the correction amount calculated from the correction gain map M (1) becomes larger than the correction amount calculated from the correction gain map M (2). With this configuration, when the engine 100 starts cranking, the correction amount of the remaining capacity can be increased.

The memory 112 has a preset time constant τ.
Store (1) and τ (2). τ (1) and τ
(2) is the decay processing time constant. These time constants are
It is used in a mathematical formula used for the electromotive force attenuation process, which will be described later. τ (1) is used in the remaining capacity calculation process executed when the engine 100 starts cranking. τ (2) is used in the remaining capacity calculation process that is executed except when the engine 100 starts cranking. τ (1) is smaller than τ (2). By doing so, the time until the electromotive force calculated using τ (1) converges to the target value is longer than the time until the electromotive force calculated using τ (2) converges to the target value. It gets shorter.

The memory 112 stores a mathematical formula (hereinafter, referred to as a mathematical formula (2)) used for the electromotive force attenuation process. This formula (2) is, for example, V (2) = V (0) + {T
/ [Tau] * (V (1) -V (0))}. V (0) is
It is the electromotive force calculated by the attenuation process executed last time. V
(1) is the electromotive force before the attenuation process is executed. V
(2) is the electromotive force after the attenuation process is executed. T
Is a constant that is stored in advance in the memory 112 and represents the processing interval. τ is the above-mentioned τ (1) and τ (2)
Is selected based on a predetermined condition.

The memory 112 stores a mathematical expression for calculating the correction amount C (hereinafter referred to as mathematical expression (3)). This formula (3) is, for example, C = G × ΔSOC. G
Represents a correction gain. The correction gain G is specified based on the battery temperature in one of the selected gain maps M (1) and M (2). ΔSOC is the estimated remaining capacity (hereinafter, referred to as SOC (1)) calculated by the first method, which is calculated from the integrated current value, and the electromotive force V (2).
To the estimated remaining capacity (hereinafter, referred to as SOC (2)) by the second method specified based on the electromotive force-remaining capacity map.

The memory 112 stores the electromotive force V (0) and the secondary battery 10 obtained by finally executing the calculation process of the remaining capacity.
4 and the processing information of the battery ECU 116 when the engine 100 was last stopped (for example,
The time at which the calculation processing of the remaining capacity is executed is stored.

The interface 114 converts analog signals from the state detection sensor 106, the ammeter 108, the voltmeter 110 and the temperature sensor 122 into digital signals,
A digital signal is transmitted to the battery ECU 116.

The battery ECU 116 detects the discharge current from the secondary battery 104 detected by the ammeter 108 and the secondary battery 10.
The current integrated value is calculated by using the charging current to No. 4. The battery ECU 116 uses the calculated integrated current value to determine the SOC
Calculate (1). The battery ECU 116 is a voltmeter 110.
The polarization voltage and the internal resistance voltage drop are calculated by using the terminal voltage detected by and the current detected by the ammeter 108. The battery ECU 116 uses the terminal voltage, the polarization voltage, and the internal resistance voltage drop and the mathematical expression (1) to calculate the electromotive force V.
Calculate (1).

The battery ECU 116 uses the state detection sensor 10
Based on the state of engine 100 detected by No. 6, it is determined whether engine 100 is about to start cranking. When the engine 100 is about to start cranking, the battery ECU
116 is a time constant τ (1) and a gain map M (1).
Select. When the engine 100 is not about to start cranking, the battery ECU 116
Selects the time constant τ (2) and the gain map M (2).

The battery ECU 116 uses the selected time constant, the gain map, the constant T representing the processing interval stored in the memory 112, and the equation (2) to calculate the electromotive force V.
Calculate (2). The battery ECU 116 uses the electromotive force-remaining capacity map to calculate S based on the calculated electromotive force V (2).
Identify OC (2). Battery ECU 116 is SOC
ΔSOC is calculated using (1) and SOC (2).

The battery ECU 116 determines the correction gain G specified from the selected gain map and the calculated ΔSOC.
Then, the correction amount C of the remaining capacity is calculated using Equation (3). Battery ECU 116 calculates the remaining capacity of secondary battery 104 by adding the calculated correction amount to SOC (1). Battery ECU 116 outputs a signal representing the calculated remaining capacity.

The monitor 118 displays the remaining capacity of the secondary battery 104 calculated by the battery ECU 116.

Referring to FIG. 4, the procedure for the remaining capacity calculation device according to the present embodiment to calculate the remaining capacity of secondary battery 104 will be described using a flowchart.

Step (hereinafter, the step will be referred to as S)
At 402, battery ECU 116 uses ammeter 108 to determine the discharge current from secondary battery 104 and secondary battery 10.
The charging current to 4 is detected. Battery ECU 116 calculates a current integrated value based on the detected current. Battery E
The CU 116 calculates the polarization voltage and the internal resistance voltage drop of the secondary battery 104. Battery ECU 116 uses state detection sensor 106 to detect whether or not engine 100 is about to start cranking.
This detection is performed using, for example, a change in acceleration when the crankshaft starts starting, a change in current discharged from the secondary battery 104, and the like.

In S404, battery ECU 116 calculates SOC (1) based on the calculated current integrated value.

At S406, battery ECU 116 detects the terminal voltage of secondary battery 104 using voltmeter 110. The battery ECU 116 uses the terminal voltage, the polarization voltage, and the internal resistance voltage drop and the mathematical expression (1) to calculate the electromotive force V.
Calculate (1).

At S408, battery ECU 116 determines whether or not engine 100 is about to start cranking, based on the time when the engine starts to start, which is detected by state detection sensor 106. When engine 100 is about to start cranking (YES in S408), the process proceeds to S410. When it is not when engine 100 is about to start cranking (NO in S408), the process proceeds to S
Moving to 412.

At S410, battery ECU 116 sets time constants τ (1) and τ stored in memory 112.
Select τ (1) from (2). Battery ECU11
6 selects the gain map M (1) from the gain maps stored in the memory 112. Thereafter, the process proceeds to S414.

At S412, battery ECU 116 selects τ (2) from time constants τ (1) and τ (2) stored in memory 112. Battery ECU 116 selects gain map M (2) from the gain maps stored in memory 112. After that, the process is S4.
Go to 14.

At S414, battery ECU 116 determines τ
Using either the time constant of (1) or τ (2), the constant T representing the processing interval, the electromotive force V (1), the previously calculated electromotive force V (0), and equation (2), Electric power V (2)
To calculate.

At S416, battery ECU 116 calculates SOC (2) based on calculated electromotive force V (2).

At S418, battery ECU 116 determines that SO
The difference (ΔSOC) between C (1) and SOC (2) is calculated.

At S420, battery ECU 116 calculates correction amount C using correction gain G, calculated ΔSOC and equation (3).

At S422, battery ECU 116 determines that the SO
Add ΔSOC to C (1). The calculated value becomes the remaining capacity of the secondary battery 104. Battery ECU 116 transmits to monitor 118 a signal indicating the remaining capacity. Battery ECU 116 ends the process of calculating the remaining capacity of secondary battery 104.

The operation of the state-of-charge calculation apparatus according to the present embodiment based on the above-described structure and flowchart will be described for different cases.

[At the start of cranking] When the user starts the engine 100, the ammeter 108 turns on the secondary battery 104.
Detects the current discharged from. The integrated current value, the polarization voltage of the secondary battery 104, and the internal resistance voltage drop are calculated based on the detected current. The state detection sensor detects the state of the engine 100 (S402). SOC
(1) is calculated based on the calculated integrated current value (S404).

The voltmeter 110 measures the terminal voltage of the secondary battery 104. The electromotive force V (1) is calculated from the terminal voltage, the polarization voltage, the internal resistance voltage drop and the mathematical expression (1) (S406).

When the battery ECU 116 determines that cranking is about to start (S4
(YES at 08), the gain map M (1) and the time constant τ (1) are selected (S410).

As the electromotive force V (2), the previously calculated electromotive force V (0), the processing interval T, the selected time constant τ (1) and the mathematical expression (2) stored in the memory 112 are used. Is calculated (S414).

SOC (2) is the calculated electromotive force V
It is specified based on (2) and the gain map (FIG. 3) stored in the memory 112 (S416). SO
ΔSOC, which is the difference between C (1) and SOC (2), is calculated (S418). The correction amount C is the calculated ΔSO
C, the correction gain G specified from the selected gain map M (1), and the mathematical expression (3) are used to calculate (S
420).

The remaining capacity of the secondary battery 104 is SOC
It is calculated using (1) and the calculated correction amount (S
422). When the remaining capacity of the secondary battery 104 is calculated,
The battery ECU 116 is a monitor 118 arranged in the driver's seat.
Then, a signal for notifying the remaining capacity is transmitted.

FIG. 5 shows the transition of the remaining capacity calculated when the engine 100 starts cranking. In the calculation process, the gain map M (1) and the time constant τ (1) are selected. Battery ECU 116 calculates a correction amount that is larger than the correction amount that is calculated during normal times, that is, except when engine 100 is about to start cranking. The time required for the calculated remaining capacity to converge to the actual remaining capacity is shorter than the time required for the calculated remaining capacity to converge to the actual value. As a result, the remaining capacity calculated by the battery ECU 116 converges on the actual remaining capacity of the secondary battery 104 faster than in normal times.

[Except when cranking starts]
When starting, the ammeter 108 detects the current discharged from the secondary battery 104 based on a predetermined interval of the remaining capacity calculation process. Integrated current value, secondary battery 10
The polarization voltage and internal resistance voltage drop of No. 4 are calculated based on the detected current. The state detection sensor detects the state of the engine 100 (S402). SOC (1)
Is calculated based on the calculated integrated current value (S
404).

The voltmeter 110 measures the terminal voltage of the secondary battery 104. The electromotive force V (1) is calculated from the terminal voltage, the polarization voltage, the internal resistance voltage drop and the mathematical expression (1) (S406).

When battery ECU 116 determines that it is not the time to start cranking (NO in S408), gain map M (2) and time constant τ (2) are selected (S412). ).

As the electromotive force V (2), the previously calculated electromotive force V (0), the processing interval T, the selected time constant τ (1) and the mathematical expression (2) stored in the memory 112 are used. Is calculated (S414).

SOC (2) is the calculated electromotive force V
(2) and the gain map (FIG. 2) stored in the memory 112 (S416). SOC
ΔSOC, which is the difference between (1) and SOC (2), is calculated (S418). The correction amount C is calculated based on the calculated ΔSOC, the correction gain G specified from the selected gain map M (2), and the mathematical expression (3) (S42).
0).

The remaining capacity of the secondary battery 104 is SOC
It is calculated using (1) and the calculated correction amount (S
422). When the remaining capacity of the secondary battery 104 is calculated,
The battery ECU 116 is a monitor 118 arranged in the driver's seat.
Then, a signal for notifying the remaining capacity is transmitted.

FIG. 6 shows the transition of the remaining capacity calculated when the engine is not about to start cranking. In this case, there is no large difference between the actual value of the remaining capacity and the value calculated by the battery ECU 116. In the remaining capacity calculation process, the gain map M (2) and the time constant τ (2) are selected. As a result, the battery ECU 116
Calculates a correction amount specified in advance, and the calculated remaining capacity converges within a predetermined time. As a result, the transition of the remaining capacity calculated by the battery ECU 116 follows the transition of the actual remaining capacity of the secondary battery 104.

FIG. 7 shows the transition of the remaining capacity corrected by the conventional remaining capacity calculating device. In this case, the calculation device does not change the parameters (for example, gain map, time constant, etc.) used for the correction process based on the determination as to whether or not the engine 100 is about to start cranking. The calculation device executes the correction process of the remaining capacity based on the gain map and the time constant stored in advance.

Therefore, for example, when the process of calculating the remaining capacity of the secondary battery 104 whose remaining capacity has decreased due to natural discharge is executed, until the calculated remaining capacity value converges to the actual remaining capacity value, It takes time. During this period, the remaining capacity meter continues to display the decrease in the remaining capacity even though the secondary battery 104 is charged.

In this way, the calculation process of the remaining capacity is
The parameter used for the calculation process is selected based on the determination as to whether or not the engine is starting to start (for example, starting cranking). The user
By referring to the monitor 118 installed in the driver's seat, the remaining capacity of the secondary battery 104 calculated when the engine 100 starts cranking can be confirmed.

Therefore, for example, when the remaining capacity decreases due to natural discharge or the like, the value of the remaining capacity is updated to a value corresponding to the decrease by the calculation process executed when the engine 100 starts cranking. To be done. As a result, the monitor 118 displays highly accurate remaining capacity information.

As described above, the remaining capacity of the secondary battery can be corrected based on the current, the voltage and the timing when the engine starts starting, corresponding to the time when the user starts the engine. As a result, it is possible to provide a highly accurate remaining capacity calculation device that corrects the remaining capacity based on the time when the secondary battery is discharged to the load and can calculate the remaining capacity of the secondary battery with high accuracy.

The characteristic value used for the process of calculating the remaining capacity is determined by the battery ECU 116 at a position where the auxiliary electric component can be used due to the discharge of the secondary battery (for example, the ignition key ACC (accessory)). The position may be selected based on the time when the position) is detected.

It should be considered that the embodiments disclosed this time are illustrative and not restrictive in all respects. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

[Brief description of drawings]

FIG. 1 is a configuration of a secondary battery remaining capacity calculation device according to an embodiment of the present invention.

FIG. 2 is a gain map (No. 1) used by the secondary battery remaining capacity calculation device according to the embodiment of the present invention.

FIG. 3 is a gain map (No. 2) used by the secondary battery remaining capacity calculation device according to the embodiment of the present invention.

FIG. 4 is a flowchart showing a process performed by the secondary battery remaining capacity calculation device according to the embodiment of the present invention.

FIG. 5 is a diagram (No. 1) showing the transition of the remaining capacity in the process performed by the remaining capacity calculation device for a secondary battery according to the embodiment of the present invention.

FIG. 6 is a diagram (No. 2) showing the transition of the remaining capacity in the processing performed by the remaining capacity calculation device for a secondary battery according to the embodiment of the present invention.

FIG. 7 is a diagram showing the transition of the remaining capacity in the processing performed by the conventional remaining capacity calculation device for a secondary battery.

[Explanation of symbols]

100 engine, 102 I / G switch, 104
Secondary battery, 106 state detection sensor, 108 ammeter,
110 voltmeter, 112 memory, 114 I / F, 1
16 battery ECU, 118 monitor, 120 auxiliary electrical equipment, 122 temperature sensor.

Continued front page    F term (reference) 2G016 CA03 CB01 CB12 CB21 CB31                       CC01 CC02 CC03 CC04 CC06                       CC07 CC12 CC13 CC23 CC27                       CC28 CE00 CF06                 5H030 AA06 AS08 FF42 FF44                 5H115 PC06 PG04 PI16 PI29 PI30                       PU01 QA01 QA10 QN03 TI02                       TI05 TI06 TI10 TR19 TU17                       UB01 UB05 UB08 UB11

Claims (12)

[Claims] 1. A remaining capacity calculation device for calculating a remaining capacity of a secondary battery connected to a load, the current detection being connected to the secondary battery and detecting a charge / discharge current of the secondary battery. Means, a voltage detection means connected to the secondary battery, for detecting the voltage of the secondary battery, and a detection means for detecting the timing at which discharge from the secondary battery to the load is started. Connected to the current detection means, the voltage detection means and the detection means, corresponding to the detected time, based on the detected current and the detected voltage,
A remaining capacity calculating device, comprising: a calculating unit for calculating the remaining capacity of the secondary battery. 2. The detecting means includes means for detecting a time when discharge to the load is started based on either the detected current or the detected voltage. The state-of-charge calculation device described in. 3. The remaining capacity calculation device, an information storage means for storing information that realizes two or more methods for calculating the remaining capacity of the secondary battery, and the information storage means corresponding to the detected time. And a method selecting means for selecting one method from the two or more stored methods, wherein the calculating means includes the detected current, the detected voltage, and the selected voltage. The remaining capacity calculating device according to claim 1, further comprising means for calculating a remaining capacity of the secondary battery based on a method. 4. The remaining capacity calculation device is connected to a storage unit for storing two or more parameters calculated in advance based on the characteristic value of the secondary battery, and the storage unit and the storage unit. Further comprising: selecting means for selecting one parameter from the two or more stored parameters corresponding to the detected time, wherein the calculating means includes the detected current and the detected current. The remaining capacity calculation device according to claim 1 or 2, further comprising means for calculating a remaining capacity of the secondary battery based on the selected voltage and the selected parameter. 5. The remaining capacity calculation device is a device for calculating a remaining capacity of a secondary battery connected to a power source for driving a vehicle, wherein the detection means is a timing at which the power source starts to start. The remaining capacity calculation device according to any one of claims 1 to 4, comprising means for detecting. 6. The remaining capacity calculating device is a device for calculating a remaining capacity of a secondary battery connected to a power source for driving a vehicle and auxiliary electric components of the vehicle, wherein the detection means is The remaining capacity calculation device according to any one of claims 1 to 4, further comprising means for detecting a time when the use of the auxiliary electric component is started. 7. A remaining capacity calculation method for calculating a remaining capacity of a secondary battery connected to a load, comprising: a current detection step of detecting a charging / discharging current of the secondary battery; A voltage detection step of detecting, a detection step of detecting a time when discharge from the secondary battery to the load is started, and the detected current and the detected voltage corresponding to the detected time. And a calculation step of calculating the remaining capacity of the secondary battery based on the above. 8. The method according to claim 7, wherein the detecting step includes a step of detecting a timing at which discharge to the load is started, based on either the detected current or the detected voltage. How to calculate the remaining capacity. 9. The method for calculating the remaining capacity comprises an information preparing step of preparing information for realizing two or more methods for calculating the remaining capacity of the secondary battery, and a step of corresponding to the detected time, The method further comprises a method selecting step of selecting one method from the two or more prepared methods, wherein the calculating step is based on the detected current, the detected voltage and the selected method. And including a step of calculating a remaining capacity of the secondary battery.
The remaining capacity calculation method described in. 10. The method for calculating the remaining capacity includes a preparatory step of preparing two or more parameters calculated in advance based on a characteristic value of the secondary battery, and the preparatory step corresponding to the detected time. Further comprising the step of selecting one parameter from the two or more parameters that have been set, the calculating step based on the detected current, the detected voltage, and the selected parameter,
The remaining capacity calculation method according to claim 7, further comprising a step of calculating a remaining capacity of the secondary battery. 11. The remaining capacity calculation method is a method for calculating a remaining capacity of a secondary battery connected to a power source for driving a vehicle, wherein the detecting step is performed when the power source starts to start. The remaining capacity calculation method according to any one of claims 7 to 10, comprising a step of detecting. 12. The remaining capacity calculation method is a method of calculating a remaining capacity of a secondary battery connected to a power source for driving a vehicle and auxiliary electric components of the vehicle, wherein the detecting step includes: The remaining capacity calculation method according to claim 7, further comprising a step of detecting a time when the auxiliary electric component is started to be used.