JP2002303658A - Method and apparatus for calculating correction coefficient for charged capacity state in battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To calculate a correction coefficient for detecting a value for indicating a state regarding the actual charged capacity of a battery according to a value in a static state. SOLUTION: The value of pure resistance in a static state corresponding to the current closed circuit voltage OCV of a battery 13 obtained from an open circuit voltage measurement means 23B is identified by a static pure resistance identification means 23C according to closed circuit voltage-pure resistance characteristics in a static state being stored in a characteristic storage means 27. A value obtained by dividing the difference between the value and the current pure resistance value of the battery 13 obtained by a pure resistance measurement means 23A by the value of the pure resistance in the battery 13 in static state that is identified by the static pure resistance value identification means 23C is obtained by an operation means 23D, and the value is calculated as a correction coefficient that is multiplied to a value for indicating state regarding the charged capacity of the battery 13 in static state for obtaining a value for indicating a state regarding the actual charged capacity in the battery 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery for supplying electric power to a vehicle load, based on a charging current or a discharging current periodically measured during charging or discharging and a terminal voltage. An open circuit voltage corresponding to the terminal voltage is calculated, and a value indicating a state related to the actual charge capacity of the battery is detected from a value indicating a state related to the charge capacity of the battery in the static state detected based on the open circuit voltage. The present invention relates to a method and an apparatus for calculating a correction coefficient according to a difference between a current state and a static state of a battery, which are used at the time.

[0002]

2. Description of the Related Art A battery mounted on a vehicle, particularly in an electric vehicle using a motor as a sole propulsion drive source, corresponds to gasoline in a vehicle using a general engine as a propulsion drive source. State SOC (Stat
It is very important to recognize how much the battery is charged, such as e of charge, in order to ensure normal running of the vehicle.

[0003] In recent years, in general vehicles using an engine as a propulsion power source, and hybrid vehicles in which a shortage of power generated by an engine is assisted by a motor, from the viewpoint of environmental protection, the vehicle is stopped when waiting at an intersection at a traffic light or the like. Equipped with an idle stop function to stop the engine.

In a vehicle equipped with this function, when the engine is restarted, a considerably large current is discharged to the starter motor and the power assisting motor also serving as the starter motor. If the battery does not have a dischargeable capacity that can withstand the large current discharge, the idle stop cannot be performed violently.

[0005] Therefore, it is necessary to accurately grasp the state regarding the charge capacity of the battery mounted on the vehicle, such as the above-mentioned state of charge SOC and the dischargeable capacity indicating how much dischargeable capacity remains in the battery. This is very important not only for the electric vehicles described above, but also for ordinary vehicles and hybrid vehicles.

[0006] Therefore, a method of determining the state of charge of the battery by determining the terminal voltage in the open circuit state of the battery, which is correlated with the state of charge of the battery SOC, and a method of integrating the charge / discharge current of the battery by time. A current integration method and a power integration method for obtaining a current dischargeable capacity of a battery by adding or subtracting a value or a discharge current integrated value to or from a dischargeable capacity of a battery before charging / discharging have already been proposed.

[0007] By the way, the battery deteriorates due to repetition of charging and discharging, or the battery (or its periphery) changes.
If the temperature of the battery changes, the pure resistance of the battery changes. Due to the change of the pure resistance, the state of the battery, such as the state of charge and the dischargeable capacity of the battery, also changes depending on the deterioration and temperature of the battery. Although it is known to fluctuate, the values indicating the state regarding the charge capacity obtained by the above-described method are all values in a static state in which the deterioration due to the battery and the fluctuation due to the temperature are not taken into consideration.

For this reason, the state of charge SOC determined from the terminal voltage in the open circuit state of the battery and the dischargeable capacity of the battery determined by the current integration method or the power integration method are corrected in accordance with the deterioration and temperature of the battery. Accordingly, it is necessary to accurately grasp the actual state regarding the charge capacity of the battery.

At present, the state of charge of the battery SO
By collecting data such as C and dischargeable capacity for various degrees of deterioration and temperatures, and calculating correlations between them, it is necessary to obtain in advance the correction coefficients used for the above-mentioned corrections by experiment for each battery specification. It is believed that there is.

[0010]

According to the concept described above, the necessity of managing the state relating to the charge capacity of a battery has been raised in vehicles using a motor as a propulsion drive source, such as electric vehicles and hybrid vehicles. However, recently, it has been recognized that the necessity of managing the state related to the charge capacity of the battery is being realized even in a vehicle that does not use a motor as a propulsion drive source.

However, for a battery such as a nickel-metal hydride battery used in a vehicle using a motor as a propulsion drive source, when the battery is depleted, the motor serving as the propulsion drive source does not operate. In contrast to batteries that do not use a motor as a propulsion drive source, batteries such as lead batteries, which are conventionally used, can operate the engine as long as fuel such as gasoline is not exhausted. Actually, the characteristic management is relatively loose compared to such a battery.

[0012] Therefore, in the case of a battery such as a lead battery, the allowable range of the characteristic difference between the individual batteries is larger than that of a battery such as a nickel-metal hydride battery even with the same specifications. If the correction coefficient obtained in advance by experiment is used as it is for all batteries of the same specification, correct correction according to each individual may not be possible, and to prevent this, batteries such as lead batteries are also required. If the management of production characteristics is made as strict as that of a battery such as a nickel-metal hydride battery, the yield of products may be deteriorated as compared with the current state.

The present invention has been made in view of the above circumstances,
An object of the present invention is to provide a battery, such as a lead battery, in which the permissible range of the characteristic difference between individuals is larger than a battery, such as a nickel metal hydride battery, even with the same specifications, and the charge capacity of the battery in a static state. A correction coefficient corresponding to a difference between the current state and the static state of the battery, which is used when detecting a value indicating the state of the actual charge capacity of the battery from the value indicating the state regarding the battery, is accurately calculated. It is an object of the present invention to provide a battery charge capacity state detection correction coefficient calculation method and a battery charge capacity state detection correction coefficient calculation apparatus suitable for use in performing this method.

[0014]

In order to achieve the above object, the present invention according to the first to eleventh aspects relates to a method of calculating a correction coefficient for detecting a state of charge of a battery. The present invention described in No. 22 relates to a correction coefficient calculation device for detecting a charged capacity state of a battery.

According to a first aspect of the present invention, there is provided a method for calculating a correction coefficient for detecting a charged state of a battery, the method comprising the steps of periodically measuring the battery supplying power to a vehicle load during charging and discharging. An open circuit voltage corresponding to a terminal voltage of the battery in an equilibrium state is calculated based on the charge current and the discharge current of the battery and the terminal voltage, and based on the open circuit voltage calculated during charging and discharging of the battery. Determine a value indicating a state related to the charge capacity of the battery in a static state without a state change due to deterioration and temperature fluctuation,
By correcting the value in the static state by a correction coefficient corresponding to the difference between the current state and the static state of the battery corresponding to the current degree of deterioration and the current temperature of the battery, A method for calculating the correction coefficient corresponding to a current state of the battery when detecting a value indicating a state of a battery regarding an actual charge capacity, the method comprising: An open circuit voltage-pure resistance characteristic indicating a correlation with a circuit voltage is determined in advance, and the battery has a constant load with a current value sufficient to eliminate at least charge-side polarization generated in the battery immediately before discharging. When discharging, based on the terminal voltage and the discharging current of the battery periodically measured, the current state of the battery corresponding to the state related to the actual charge capacity of the battery. A resistance is obtained, and a current open circuit voltage of the battery is obtained based on a terminal voltage of the battery measured before the start of the constant load discharge, and the battery corresponding to the obtained current open circuit voltage of the battery is obtained. The value of the pure resistance in the static state of the battery is calculated from the predetermined open circuit voltage-pure resistance characteristic, and the pure battery in the static state of the determined battery corresponding to the obtained current open circuit voltage of the battery is calculated. The difference between the resistance value and the current pure resistance value of the battery determined at the time of the constant load discharge of the battery is divided by the determined pure resistance value of the battery in a static state. Calculated as the correction coefficient corresponding to the current state of the battery.

Further, the method of calculating the correction coefficient for detecting the state of charge of the battery according to the present invention as defined in claim 2 is according to claim 1.
In the method for calculating the correction coefficient for detecting the charged capacity state of a battery according to the present invention, the battery has a constant load discharge with a current value sufficient to eliminate at least a charge-side polarization generated in the battery immediately before discharging. From the battery terminal voltage and the discharge current that are periodically measured when performing the first, the first of the voltage-current characteristics showing the correlation between the battery terminal voltage and the discharge current during the increase of the discharge current An approximate curve expression and a second approximate curve expression of the voltage-current characteristic indicating a correlation between the terminal voltage of the battery and the discharge current during the decrease of the discharge current are obtained, and are represented by the first approximate curve expression. A first point on the voltage-current characteristic curve
A second point is defined on each of the voltage-current characteristic curves represented by the second approximate curve expression, and a second voltage drop occurs when a second discharge current corresponding to the second point flows. The first assumed point having the same resistance value as the second combined resistance including the pure resistance of the battery and the second polarization resistance component is set to a voltage-represented by the first approximate curve expression.
A first resistor composed of a pure resistance of the battery and a first polarization resistance component, which is assumed on a current characteristic curve and causes a first voltage drop when a first discharge current corresponding to the first point flows. A second assumed point having the same resistance value as the combined resistance of No. 1 is defined as a voltage-represented by the second approximate curve equation.
Assuming on a current characteristic curve, a first slope of a straight line connecting the second point and the first assumed point is determined by the second discharge current and the discharge current at the first assumed point. The first correction slope excluding the voltage drop due to the second polarization resistance component is obtained by correcting the amount corresponding to the difference between the voltage drops due to the second polarization resistance component, and the first correction slope. A second slope of a straight line connecting a point and the second assumed point, a voltage caused by the first polarization resistance component, which is caused by the first discharge current and the discharge current at the second assumed point, respectively. An amount corresponding to the difference between the drops is corrected to obtain a second correction slope excluding the voltage drop due to the first polarization resistance component, and the obtained first and second slopes are averaged to obtain an average slope. To determine the average slope of the battery at the current net resistance of the battery. It was as determined as.

Further, according to a third aspect of the present invention, there is provided a method of calculating a correction coefficient for detecting a state of charge of a battery according to the second aspect of the present invention. An arbitrary point within a range where the terminal voltage and the discharge current of the battery are measured to obtain the first approximate curve equation and the second approximate curve equation. It was made to be.

Further, according to the present invention, there is provided a method of calculating a correction coefficient for detecting a state of charge of a battery according to the present invention.
In the method of calculating a correction coefficient for detecting a charged capacity state of a battery according to the present invention described in 3 or 3, the first point and the second
And the maximum current of the discharge current of the battery measured to obtain the first approximate curve equation and the second approximate curve equation on the first approximate curve equation and the second approximate curve equation. A point corresponding to the value was set.

Further, according to a fifth aspect of the present invention, there is provided a method for calculating a correction coefficient for detecting a state of charge of a battery according to the present invention. In the method, in obtaining the first approximate curve equation and the second approximate curve equation, the terminal voltage and the discharge current of the battery measured periodically are collected, stored, and stored for the latest predetermined time. I tried to keep it.

Further, according to the present invention, there is provided a method for calculating a correction coefficient for detecting a charged capacity state according to the present invention.
In the method for calculating a correction coefficient for detecting a charged capacity state of a battery according to the present invention described in 4 or 5, the battery is charged for a predetermined time after a predetermined time has elapsed after charging or discharging of the battery is completed. The open-circuit voltage is measured a plurality of times, and a predetermined power-approximation equation whose power is negative is determined by the difference value between the measured open-circuit voltage and the assumed open-circuit voltage, and the determined power-approximation equation is determined. Is repeatedly performed while updating the assumed open circuit voltage until the exponent reaches −0.5 or approximately −0.5. 5 or approximately −0.
The assumed open circuit voltage at the time of 5 is obtained as the current open circuit voltage of the battery.

Further, according to a seventh aspect of the present invention, there is provided a method for calculating a correction coefficient for detecting a state of charge of a battery according to the sixth aspect of the present invention. When the measured open-circuit voltage is after the end of the charging of the battery, and the time is t, the unknown coefficient is α, and the unknown negative exponent is D, the power approximation equation is α · t ^D It was assumed to be represented by

Further, the method of calculating a correction coefficient for detecting the state of charge of a battery according to the present invention described in claim 8 is as defined in claim 6.
In the method of calculating a correction coefficient for detecting the state of charge of a battery according to the present invention, when the measured open-circuit voltage is after the end of discharging of the battery, the power-approximation expression is determined. The value is an absolute value of a value obtained by subtracting the assumed open circuit voltage from the measured open circuit voltage, and when the time is t, the unknown coefficient is α, and the unknown negative power is D, the power approximation is used. The equation was represented by α · t ^D.

Further, according to a ninth aspect of the present invention, there is provided a method of calculating a correction coefficient for detecting a state of charge of a battery according to the present invention. The open-circuit voltage measured during the fixed time is an arbitrary number of 2 or more, and the open-circuit voltage obtained by the measurement and the time from the end of charging / discharging are regression-calculated to perform the power approximation. Is determined.

According to a tenth aspect of the present invention, there is provided a method of calculating a correction coefficient for detecting a state of charge of a battery according to the present invention. In the correction coefficient calculation method for use, the open voltage of the battery is changed during a period of time elapsed after the charging or discharging of the battery is completed to reach a predetermined second time from a predetermined first time. Measured a plurality of times, from the measured open-circuit voltage, after the charging or discharging of the battery is completed, the open-circuit voltage with respect to a period from the first time period to the second time period, Determining a predetermined linear approximation, indicating a correlation with the elapsed time from the end of the charge or discharge, longer than the second time,
The solution of the determined linear approximation when the predetermined third time is substituted as the elapsed time from the end of charging or discharging of the battery is obtained as the current open circuit voltage of the battery. .

Further, the method of calculating the correction coefficient for detecting the state of charge of the battery according to the present invention according to claim 11 is the method of calculating the correction coefficient for detecting the state of charge of the battery according to claim 10 of the present invention. Assuming that the elapsed time from the end of charging or discharging of the battery is t, the unknown coefficient is c, and the unknown complement is E, the linear approximation formula is represented by c · t + E.

Further, according to a twelfth aspect of the present invention, there is provided a correction coefficient calculating apparatus for detecting a charged state of a battery, as shown in the basic configuration diagram of FIG. An open circuit voltage corresponding to a terminal voltage of the battery 13 in an equilibrium state is calculated based on a charging current and a discharging current of the battery 13 and a terminal voltage which are periodically measured during and during discharging. Based on the open circuit voltage calculated during charging or discharging, a value indicating a state related to the charge capacity of the battery 13 in a static state without a state change due to deterioration and temperature fluctuation is obtained,
The value in the static state is corrected by a correction coefficient according to the difference between the current state and the static state of the battery 13 corresponding to the current deterioration degree and the current temperature of the battery 13. An apparatus for calculating a correction coefficient corresponding to a current state of the battery 13 in detecting a value indicating a state of the battery 13 with respect to an actual charge capacity, wherein the pure resistance in a static state of the battery 13 is Circuit means 2 in which an open circuit voltage-pure resistance characteristic indicating a correlation between the open circuit voltage and the open circuit voltage of the battery 13 is stored in advance.
7 and the battery 13 periodically measured when the battery 13 performs a constant load discharge at a current value sufficient to eliminate at least a charge-side polarization generated in the battery 13 immediately before discharging. A pure resistance measuring unit 23A for obtaining a current pure resistance of the battery 13 corresponding to a state related to an actual charge capacity of the battery 13 based on the terminal voltage and the discharge current of the battery 13; An open circuit voltage measuring means 23B for obtaining a current open circuit voltage of the battery 13 based on the measured terminal voltage of the battery 13, and an open circuit voltage measuring means 23B
The static resistance value of the battery 13 in the static state corresponding to the current open circuit voltage of the battery 13 obtained from the above is calculated from the open circuit voltage-pure resistance characteristic stored in the characteristic storage means 27. Pure resistance value determining means 2
3C and the pure state in the static state of the battery 13 corresponding to the current open circuit voltage of the battery 13 determined by the open circuit voltage measuring means 23B determined by the static pure resistance value determining means 23C. The resistance value and the pure resistance measuring means 23A during the constant load discharge of the battery 13
The difference value between the current pure resistance value of the battery 13 and the current pure resistance value of the battery 13 determined by the open circuit voltage measuring means 23B determined by the static pure resistance value determining means 23C. Calculating means 23D for calculating a value obtained by dividing by a value of the pure resistance in a static state of the battery 13 corresponding to the open circuit voltage of the battery 13;
A value obtained by 3D is calculated as the correction coefficient corresponding to the current state of the battery 13.

Further, according to a thirteenth aspect of the present invention, there is provided a battery charge capacity state detecting correction coefficient calculating apparatus according to the twelfth aspect, wherein the battery charging capacity state detecting correction coefficient calculating apparatus according to the twelfth aspect is provided. Pure resistance measuring means 23
A is periodically measured at the time of constant load discharge with a current value sufficient to eliminate the charging-side polarization that has occurred in the battery 13 at least immediately before discharge of the battery 13,
A first approximate curve expression of the voltage-current characteristic showing a correlation between the terminal voltage of the battery 13 and the discharge current during the increase of the discharge current, based on the terminal voltage of the battery 13 and the discharge current; Approximate curve equation calculating means 23E for obtaining a second approximate curve equation of the voltage-current characteristic indicating the correlation between the terminal voltage of the battery 13 and the discharge current in the battery.
And a second voltage drop when a second discharge current corresponding to a second point defined on the voltage-current characteristic curve represented by the second approximate curve equation is caused. A first assumed point having the same resistance value as the first combined resistance composed of the pure resistance and the first polarization resistance component is assumed on the voltage-current characteristic curve represented by the first approximate curve equation. And a first voltage drop when a first discharge current corresponding to a first point defined on a voltage-current characteristic curve represented by the first approximate curve expression flows. A second assumed point having the same resistance value as the second combined resistance comprising the pure resistance and the second polarization resistance component is assumed on the voltage-current characteristic curve represented by the second approximate curve expression. And a straight line connecting the second point and the first assumed point. 1 is corrected by an amount corresponding to a difference in voltage drop due to the second polarization resistance component, which is caused by the second discharge current and the discharge current at the second assumed point, respectively. And the first correction slope excluding the voltage drop due to the polarization resistance component is obtained, and the second slope of a straight line connecting the first point and the second assumed point is defined as the first discharge current and the second slope. The first current is corrected by an amount corresponding to the difference in voltage drop due to the first polarization resistance component, which is caused by the discharge current at the second assumed point, and
A second correction slope obtained by removing the voltage drop due to the polarization resistance component of the second calculation slope, and averaging the obtained first correction slope and the second correction slope to obtain an average slope.
F, and the average slope determined by the second calculating means 23F is determined as the current pure resistance of the battery 13.

According to a fourteenth aspect of the present invention, in the battery charging capacity state detecting correction coefficient calculating apparatus according to the thirteenth aspect of the present invention, the battery charging capacity state detecting correction coefficient calculating apparatus according to the thirteenth aspect is provided. The first point and the second point are set to any values within a range where the terminal voltage and the discharge current of the battery 13 measured to obtain the first approximate curve expression and the second approximate curve expression are present. Points.

Further, the battery charge capacity state detecting correction coefficient calculating device of the present invention according to claim 15 is the battery charge capacity state detecting correction coefficient calculating device of the present invention according to claim 13 or 14. , The first point and the second point are defined by the first approximate curve expression and the second
On the approximation curve equation, the point corresponding to the maximum current value of the discharge current I of the battery 13 measured to obtain the first approximation curve equation and the second approximation curve equation.

The battery charge capacity state detecting correction coefficient calculating device according to the present invention as defined in claim 16 is a battery charge capacity state detecting correction coefficient calculating device according to claim 13, 14 or 15. In the apparatus, the approximate curve equation calculating means 23E calculates the first approximate curve equation and the second approximate curve equation in order to calculate the terminal of the battery 13 periodically measured during the constant load discharge of the battery 13. Collect and store voltage and discharge current for the latest predetermined time,
It has storage means 23bA for storing.

Further, according to the present invention, there is provided a battery charge capacity state detecting correction coefficient calculating apparatus according to the present invention. In the correction coefficient calculating device for battery, the open circuit voltage measuring means 23B
After the charging or discharging of the battery 3 is completed, an open-circuit voltage measuring means 23G for measuring the open-circuit voltage of the battery 13 for a predetermined time after a predetermined time has elapsed, and a plurality of times by the open-circuit voltage measuring means 23G. A difference value between a plurality of open-circuit voltages obtained by measurement and an assumed open-circuit voltage OCV ′,
An approximate expression determining means 23H for determining a predetermined power-approximation expression having a negative power, and the power of the power-approximation expression determined by the approximate expression determining means 23H is -0.5, or
Calculation control means 23J for causing the approximation equation determination means 23H to repeatedly update the assumed open circuit voltage and execute the determination of the power approximation equation until the value becomes approximately -0.5;
The assumed open circuit voltage when the exponent is -0.5 or substantially -0.5 is determined as the current open circuit voltage of the battery 13.

Further, according to the present invention, there is provided a correction coefficient calculating apparatus for detecting a state of charge of a battery according to the present invention, wherein the correction coefficient calculating apparatus for detecting a state of charge of a battery according to the present invention is provided. When the measured open circuit voltage is obtained after the charging of the battery 13, the time is t, the unknown coefficient is α, and the unknown negative power is D.
, The power approximation equation is represented by α · t ^D.

Further, according to a nineteenth aspect of the present invention, in the battery charging capacity state detecting correction coefficient calculating device according to the seventeenth aspect of the present invention, the battery charging capacity state detecting correction coefficient calculating device is provided. When the measured open circuit voltage is after the end of discharging of the battery 13, the value for determining the power approximation equation is obtained by subtracting the assumed open circuit voltage from the measured open circuit voltage. If the time is t, the unknown coefficient is α, and the unknown negative exponent is D, the power approximation formula is α · t
^D.

According to a twentieth aspect of the present invention, there is provided a battery charge capacity state detecting correction coefficient calculating device according to the eighteenth or nineteenth aspect of the present invention. The approximate expression determining means 2
3H performs a regression calculation process on an arbitrary number of two or more open voltages measured by the open voltage measuring means 23G during the predetermined time and a time from the end of charging / discharging to calculate a power D of the power approximation formula. It was decided.

Further, according to a twenty-first aspect of the present invention, there is provided a correction coefficient calculating device for detecting a state of charge of a battery according to the present invention. In the correction coefficient calculation device for use, as shown in the basic configuration diagram of FIG. 2, the open circuit voltage measuring means sets the elapsed time after the charging or discharging of the battery 13 ends from a predetermined first time. A second open-circuit voltage measuring means 23K for measuring an open-circuit voltage of the battery 13 until a predetermined second time;
From the plurality of open-circuit voltages obtained by the open-circuit voltage measuring means 23K measured a plurality of times, after the charging or discharging is completed, the period from when the first time elapses to when the second time elapses. A second approximation expression determining unit 23L for determining a predetermined linear approximation expression indicating a correlation between the open-circuit voltage and the elapsed time from the end of the charging or discharging, and a predetermined approximation longer than the second time. Calculating means 23M for calculating the solution of the linear approximation determined by the second approximate expression determining means 23L when the third time is substituted as the elapsed time from the end of the charging or discharging. The solution calculated by the calculating means 23M is determined as the current open circuit voltage of the battery 13.

According to a twenty-second aspect of the present invention, in the battery charge capacity state detecting correction coefficient calculating device according to the twenty-first aspect of the present invention, the battery charge capacity state detecting correction coefficient calculating device calculates the battery charged state detecting correction coefficient. Assuming that the elapsed time from the end of charge or discharge of 13 is t, the unknown coefficient is c, and the unknown complement is E, the linear approximation formula is represented by c · t + E.

According to the method of calculating the correction coefficient for detecting the state of charge of a battery according to the first aspect of the present invention, the terminal voltage in the state of equilibrium of the battery, which is used for obtaining a value indicating the state related to the state of charge of the battery. The current value of the open circuit voltage corresponding to at least based on the terminal voltage of the battery measured before the start of the constant load discharge with a current value sufficient to eliminate at least the charging side polarization occurring immediately before the discharge. When obtained, the value is a value in a static state in which the change due to battery deterioration or temperature is not reflected.

When the state related to the charge capacity of the battery changes due to deterioration or temperature, the pure resistance of the battery changes from the pure resistance in the static state where the state does not change due to deterioration and temperature fluctuation. When the difference between the values of the net resistance and the static resistance is divided by the net resistance in the static state, the value indicates the degree of change of the state regarding the actual charge capacity of the battery with respect to the state regarding the charge capacity of the battery in the static state. Become.

Therefore, the current value of the battery, which is determined based on the terminal voltage of the battery measured before the start of the constant load discharge with a current value sufficient to eliminate at least the charge-side polarization that occurred immediately before the discharge. The open-circuit voltage-pure resistance characteristic showing the correlation between the predetermined pure resistance in the static state of the battery and the open-circuit voltage of the battery, which corresponds to the open-circuit voltage of the battery. And at least the current pure resistance of the battery based on the terminal voltage and discharge current when the battery performed a constant load discharge with a current value sufficient to eliminate at least the charging side polarization that occurred immediately before the discharge. Is calculated by dividing the difference between the obtained current pure resistance and the determined pure resistance in the static state by the value of the pure resistance in the static state. When determining the number, the value of the correction coefficient is unique to that battery, a value that indicates the actual variation of the state regarding the charge capacity of the battery to the state relating to the charge capacity of the battery at a static state.

Therefore, the battery obtained based on the terminal voltage of the battery measured at least before the start of the constant load discharge at a current value sufficient to eliminate the charge-side polarization generated immediately before the discharge is obtained. Multiplying the current open-circuit voltage by the correction coefficient specific to the battery obtained as described above, the charge capacity of the battery in a static state in which the amount of change due to deterioration or temperature of the battery is not reflected is obtained. Instead of a value indicating the state, a value indicating a state related to the actual charge capacity of the battery is detected.

According to a second aspect of the present invention, there is provided a method of calculating a correction coefficient for detecting a state of charge of a battery according to the first aspect of the present invention. The terminal current of the battery and the terminal voltage of the battery periodically measured at the time of constant load discharge at a current value sufficient to eliminate the charging side polarization generated in the battery at least immediately before the discharge, and the discharge current A first approximate curve expression of a voltage-current characteristic showing a correlation between a terminal voltage of a battery and a discharge current during an increase, and a voltage-current characteristic showing a correlation between a terminal voltage of the battery and a discharge current during a decrease of a discharge current And a second approximate curve expression of

Next, a first point is placed on the voltage-current characteristic curve represented by the first approximate curve equation, and a second point is placed on the voltage-current characteristic curve represented by the second approximate curve equation. Is defined respectively.

Then, when a second discharge current corresponding to the second point flows, a second voltage drop is generated, and the same as the second combined resistance composed of the pure resistance of the battery and the second polarization resistance component. Is assumed on the voltage-current characteristic curve represented by the first approximate curve expression, and a first discharge current corresponding to the first point flows. A second assumed point that causes the first voltage drop and has the same resistance value as the first combined resistance including the pure resistance of the battery and the first polarization resistance component is represented by the second approximate curve expression. On the voltage-current characteristic curve.

Thereafter, a first slope of a straight line connecting the second point and the first assumed point is formed by a second polarization generated by the second discharge current and the discharge current at the first assumed point, respectively. Correcting the amount corresponding to the difference in voltage drop due to the resistance component,
And a second slope of a straight line connecting the first point and the second assumed point is obtained by calculating the first slope of the first discharge current and the second slope of the second assumed point. Is corrected by an amount corresponding to the difference in voltage drop due to the first polarization resistance component, which is caused by the discharge current at the assumed point of the above, and the second correction slope excluding the voltage drop due to the first polarization resistance component is calculated. Ask.

By averaging the first correction slope and the second correction slope thus obtained, the average slope of these two correction slopes is obtained as the pure resistance of the battery. Therefore, the current pure resistance of the battery can be obtained only by processing data obtained from the terminal voltage and the discharge current of the battery periodically measured at the time of constant current discharge by a predetermined large current.

According to the third aspect of the present invention, there is provided a method for calculating a correction coefficient for detecting a state of charge of a battery according to the present invention.
In the method of calculating a correction coefficient for detecting a state of charge of a battery according to the present invention, the first point and the second point are obtained by calculating a first approximate curve equation and a second approximate curve equation. Since it is an arbitrary point within the range where the measured battery terminal voltage and discharge current exist, at least one point for obtaining the slope is based on actual data, and it is necessary to use a point that deviates greatly from the actual Can be eliminated.

According to a fourth aspect of the present invention, there is provided a method of calculating a correction coefficient for detecting a state of charge of a battery according to the present invention. In the method, a first point and a second point are defined by a first approximate curve equation and a second approximate curve equation.
Since the upper point corresponding to the maximum value of the measured discharge current of the battery for obtaining the first approximate curve equation and the second approximate curve equation is used, at least one of the points for determining the slope is converted to actual data. It is possible to eliminate the use of points that deviate greatly from the actual situation, and to make both points common, so that errors are reduced compared to those using different data. .

Further, according to the method of calculating the correction coefficient for detecting the state of charge of the battery according to the present invention,
5. The method according to claim 2, 3 or 4, wherein the first and second approximate curve expressions are obtained by periodically measuring the first approximate curve expression and the second approximate curve expression. Are collected, stored and stored for the latest predetermined time, and a first approximate curve equation and a second approximate curve equation are obtained using the stored actual data. After confirming that the necessary discharge current has flowed, the first approximate curve equation and the second approximate curve equation can be obtained.

Further, according to the method of calculating the correction coefficient for detecting the charged capacity state of the present invention as set forth in claim 6,
In the method for calculating a correction coefficient for detecting a charged capacity state of a battery according to the present invention described in 2, 3, 4, or 5, charging or discharging of a battery mounted on the vehicle to supply power to a load mounted on the vehicle is performed. After the termination, the open-circuit voltage of the battery is measured a plurality of times during a predetermined time after a predetermined time has elapsed. Next, a predetermined power-of-power approximation formula whose power is negative is determined based on the difference between the measured open circuit voltage and the assumed open circuit voltage. Until the power of the determined power approximation is -0.5 or approximately -0.5,
The power approximation is determined repeatedly by updating the assumed open circuit voltage, and the exponent becomes −0.5 or approximately −0.5.
Since the assumed open circuit voltage at the time of is obtained as the current open circuit voltage of the battery, after the charging or discharging of the battery is completed, by measuring the open circuit voltage of the battery within a relatively short time, An asymptote of a power approximation that does not change under the influence of temperature can be determined as the current open circuit voltage of the battery.

Further, according to the method of calculating the correction coefficient for detecting the state of charge of a battery according to the present invention,
In the method of calculating a correction coefficient for detecting a charged capacity state of a battery according to the present invention, when the measured open-circuit voltage is after the end of charging, the time is t, the unknown coefficient is α, and the unknown coefficient is α. Is a negative power of D, the power approximation is represented by α · t ^D , and the power ^D of the power approximation α · t ^D becomes −0.5, or approximately −0.5 and Since the assumed open-circuit voltage at the time of battery failure is determined as the current open-circuit voltage of the battery, the influence of temperature can be measured by measuring the open-circuit voltage of the battery measured within a relatively short time after the battery has been charged. As a result, an asymptote of a power approximation that does not change can be obtained, and this can be obtained as the current open circuit voltage of the battery.

According to the method of calculating the correction coefficient for detecting the state of charge of the battery according to the present invention as set forth in claim 8, the method of calculating the correction coefficient for detecting the state of charge of the battery according to claim 6 of the present invention. When the measured open circuit voltage is after the end of the discharge, the value for determining the power approximation formula is the absolute value of the value obtained by subtracting the assumed open circuit voltage from the measured open circuit voltage, the time t, the unknown coefficients alpha, when the exponent of unknown negative is D, power approximate expression is expressed in alpha · t ^D, the number D a power of power approximate expression alpha · t ^D -0.5 Or the estimated open-circuit voltage when the voltage becomes approximately -0.5 is determined as the current open-circuit voltage of the battery, so that it was measured within a relatively short time after the battery discharge was completed. Measurement of the open-circuit voltage of the battery An asymptote of the power approximation that does not change can be determined and this can be determined as the current open circuit voltage of the battery.

According to a ninth aspect of the present invention, there is provided a method for calculating a correction coefficient for detecting a state of charge of a battery according to the present invention.
9. The method according to claim 7, wherein the open-circuit voltage measured during a predetermined time is an arbitrary number of 2 or more, and the arbitrary number obtained by this measurement is an arbitrary number. The open circuit voltage is regression-calculated to determine the exponent D of the power approximation formula.
Even if the exponent D of t ^D is not −0.5, the assumed open circuit voltage when the power approximation is determined a predetermined number of times can be obtained as the current open circuit voltage of the battery. After the charge / discharge of the battery is completed, the measurement of the open-circuit voltage of the battery, which has been measured in a relatively short time,
An asymptote of a power approximation that does not change under the influence of temperature can be accurately obtained, and this can be obtained as the current open circuit voltage of the battery.

According to a tenth aspect of the present invention, there is provided a method for calculating a correction coefficient for detecting a state of charge of a battery according to the present invention.
6. The method according to claim 1, wherein the elapsed time after the end of the charging or discharging is a predetermined first time.
During the period from the time to the predetermined second time, the open-circuit voltage of the battery is measured a plurality of times, and after the charging or discharging ends from the measured open-circuit voltage, the first time elapses , A predetermined linear approximation formula indicating the correlation between the open-circuit voltage and the elapsed time from the end of charging or discharging is determined for a period from when the second time elapses. When the determined third time is substituted as the elapsed time from the end of charging or discharging, the solution of the determined linear approximation equation is obtained as the current open circuit voltage of the battery.

Further, according to the method of calculating the correction coefficient for detecting the state of charge of the battery according to the present invention as set forth in claim 11, the method of calculating the correction coefficient for detecting the state of charge of the battery according to claim 10 of the present invention. From the open time of the battery measured a plurality of times during the time elapsed from the end of the charging or discharging to the predetermined second time to the predetermined second time, the charging or discharging Assuming that the elapsed time from the end is t, the unknown coefficient is c, and the unknown complement is E, a straight-line approximation expression represented by c · t + E is determined.

Further, according to the correction coefficient calculating apparatus for detecting the state of charge of a battery according to the present invention,
As shown in FIG. 1, the current value of the open circuit voltage corresponding to the terminal voltage in the equilibrium state of the battery 13, which is used to determine the value indicating the state regarding the charge capacity of the battery 13, is generated at least immediately before discharging. When the open circuit voltage measuring means 23B obtains the value based on the terminal voltage of the battery 13 measured before the start of the constant load discharge with a current value sufficient to eliminate the charging-side polarization, the value becomes
This is a value in a static state in which a change due to deterioration or temperature of the battery 13 is not reflected.

By the way, if the state related to the charge capacity of the battery 13 changes due to deterioration or temperature, the battery 13
The pure resistance of the static state changes from the pure state resistance without the state change due to deterioration and temperature fluctuation.
The value indicates the degree of change of the state related to the actual charge capacity of the battery 13 with respect to the state related to the charge capacity of the battery 13 in the static state.

Therefore, the open circuit voltage measuring means 23B based on at least the terminal voltage of the battery 13 measured before the start of the constant load discharge with a current value sufficient to eliminate the charge-side polarization generated immediately before the discharge. Sought,
The pure resistance of the battery 13 in the static state corresponding to the current open circuit voltage of the battery 13 is determined by the pure resistance in the static state of the battery 13 stored in the characteristic storage unit 27 in advance and the open circuit of the battery 13. From the open circuit voltage-pure resistance characteristic showing the correlation with the voltage, the static pure resistance value determining means 23C
And at least a pure resistance measuring means based on a terminal voltage and a discharge current when the battery 13 performs a constant load discharge at a current value sufficient to eliminate the charge-side polarization generated immediately before the discharge. Battery 1 by 23A
3 and the current pure resistance determined by the pure resistance measuring means 23A and the static pure resistance value determining means 23C.
The value obtained by dividing the difference between the value of the pure resistance in the static state and the value of the pure resistance in the static state by the calculating means 23D is calculated by the calculating means 23D.
The value determined by D is a correction coefficient that indicates the degree of change of the state related to the actual charge capacity of the battery 13 with respect to the state related to the charge capacity of the battery 13 in the static state, which is unique to the battery 13.

Therefore, the open circuit voltage is measured based on the terminal voltage of the battery 13 measured before the start of the constant load discharge with a current value sufficient to eliminate at least the charging side polarization generated immediately before the discharge. Means 23B
Is calculated by multiplying the current open circuit voltage of the battery 13 by the correction coefficient specific to the battery 13 obtained by the calculating means 23D as described above.
A value indicating a state related to the actual charge capacity of the battery 13 is detected instead of a value indicating a state related to the charge capacity of the battery 13 in a static state in which a change due to deterioration or temperature of the battery 3 is not reflected.

Further, according to the correction coefficient calculating apparatus for detecting the charge capacity state of the battery according to the present invention, the correction coefficient calculating apparatus for detecting the charge capacity state of the battery according to the present invention is provided. , Battery 13
The discharge current increases at least from the terminal voltage and the discharge current of the battery 13 periodically measured at the time of constant load discharge with a current value sufficient to eliminate the charge-side polarization generated in the battery 13 immediately before the discharge. First approximation curve expression of the voltage-current characteristic showing the correlation between the terminal voltage of the battery 13 and the discharge current during storage, and the voltage-current characteristic showing the correlation between the terminal voltage of the battery and the discharge current during reduction of the discharge current Is calculated by the approximate curve equation calculating means 23E.

In calculating the pure resistance of the battery 13, the second calculating means 23F firstly sets the second resistance defined on the voltage-current characteristic curve represented by the second approximate curve equation.
A second voltage drop is caused when the second discharge current corresponding to the point (1) flows, and the second voltage drop has the same resistance value as the first combined resistance including the pure resistance of the battery 13 and the first polarization resistance component. Assuming the first assumed point on the voltage-current characteristic curve represented by the first approximate curve equation,
When the first discharge current corresponding to the first point defined on the voltage-current characteristic curve represented by the approximate curve expression of A second assumed point having the same resistance value as the second combined resistance including the polarization resistance component is assumed on the voltage-current characteristic curve represented by the second approximate curve expression.

Next, the second calculating means 23F calculates the first slope of the straight line connecting the second point and the first assumed point to the second discharge current and the discharge current at the second assumed point. Is corrected by an amount corresponding to the difference of the voltage drop due to the second polarization resistance component, thereby obtaining a first correction slope excluding the voltage drop due to the second polarization resistance component, The second slope of the straight line connecting the second assumed point corresponds to the difference in voltage drop due to the first polarization resistance component caused by the first discharge current and the discharge current at the second assumed point, respectively. The second correction slope is obtained by performing the amount correction and excluding the voltage drop due to the first polarization resistance component.

Finally, the second calculating means 23F adds and averages the obtained first correction slope and the second correction slope, thereby obtaining the average slope of these two correction slopes as the current slope of the battery 13. Since the battery 1 is obtained as a pure resistance, the battery 1 periodically measured at the time of constant current discharge by a predetermined large current is used.
Approximate curve expression calculating means 23 from the terminal voltage and discharge current
The current pure resistance of the battery 13 can be obtained only by processing the data obtained by E by the second calculating means 23F.

Further, according to the correction coefficient calculating apparatus for detecting the state of charge of a battery according to the present invention,
In the correction coefficient calculating apparatus for detecting a charged capacity state of a battery according to the present invention, the first point and the second point are obtained by calculating a first approximate curve equation and a second approximate curve equation. Since it is an arbitrary point within the range where the measured battery terminal voltage and discharge current exist, at least one point for obtaining the slope is based on actual data, and it is necessary to use a point that deviates greatly from the actual point. Can be eliminated.

Further, according to the battery charge capacity state detecting correction coefficient calculating device of the present invention as set forth in claim 15, the battery charge capacity state detecting correction coefficient of the present invention according to claim 13 or 14 is calculated. In the apparatus, the first point and the second point are measured on the first approximate curve equation and the second approximate curve equation to determine the first approximate curve equation and the second approximate curve equation. Since the upper point corresponding to the predetermined large current value of the discharge current of the battery 13 is used, at least one of the points for obtaining the inclination is based on the actual data, and the point that deviates greatly from the actual point is used. In addition, both points become common, and errors can be reduced as compared with those using different data.

Further, according to the battery charge capacity state detection correction coefficient calculating apparatus of the present invention,
In the battery charge capacity state detecting correction coefficient calculating apparatus according to claim 13, 14 or 15, the storage means 23bA determines a first approximate curve equation and a second approximate curve equation. Collects and stores the terminal voltage and discharge current of the battery 13 measured for the latest predetermined time,
Since the stored data is stored, it is confirmed by using the actual data stored in the storage means 23bA that the discharge current necessary for obtaining the first approximate curve equation and the second approximate curve equation has flowed. Thus, the first approximate curve expression and the second approximate curve expression can be obtained.

Further, according to the battery charging capacity state detecting correction coefficient calculating device of the present invention described in claim 17, the battery charging capacity of the present invention described in claim 12, 13, 14, 15, or 16 is provided. In the state detection correction coefficient calculating device, the open-circuit voltage measuring means 23G
After the charging or discharging of the battery is completed, the open-circuit voltage of the battery 13 is measured for a predetermined time after a predetermined time has elapsed. The approximation formula determining means 23H is provided by the open-circuit voltage measuring means 23.
A predetermined power-approximation equation having a negative exponent is determined based on a difference value between a plurality of open-circuit voltages obtained by performing a plurality of measurements using G and an assumed open-circuit voltage OCV ′. The arithmetic control means 23J determines the power approximation expression until the power of the power approximate expression determined by the approximate expression determination means 23H becomes -0.5 or approximately -0.5. The assumed open circuit voltage is updated to 23H and is repeatedly executed. Then, when the exponent becomes -0.5, or approximately -0.5
Is calculated as the current open circuit voltage of the battery 13. Therefore, after the charging or discharging of the battery 13 is completed, the open circuit voltage of the battery 13 measured within a relatively short time is calculated. By measurement, an asymptote of a power approximation that does not change under the influence of temperature can be obtained, and this can be obtained as the current open circuit voltage of the battery 13.

Further, according to the battery charge capacity state detecting correction coefficient calculating apparatus of the present invention,
In the battery charge capacity state detection correction coefficient calculating device according to the present invention as set forth in claim 17, when the measured open circuit voltage is obtained after the charging of the battery 13 is completed,
Assuming that the time is t, the unknown coefficient is α, and the unknown negative power is D, the power approximation is represented by α · t ^D , and the power approximation α ·
Since the assumed open circuit voltage when the exponent D of t ^D becomes -0.5 or becomes approximately -0.5 is obtained as the current open circuit voltage of the battery 13, the charging of the battery 13 is After completion, an asymptote of a power approximation that does not change under the influence of temperature is determined by measuring the open circuit voltage of the battery 13 measured within a relatively short time, and this is used as the current open circuit voltage of the battery 13. You can ask.

Further, according to the battery charging capacity state detecting correction coefficient calculating apparatus of the present invention described in claim 19, the battery charging capacity state detecting correction coefficient calculating apparatus of the present invention according to claim 17 is provided. When the measured open-circuit voltage is obtained after the discharge of the battery 13 is completed, the value for determining the power approximation formula is an absolute value of a value obtained by subtracting the assumed open-circuit voltage from the measured open-circuit voltage. in and, t the time, the unknown coefficients alpha, when the exponent of unknown negative and D, power approximate expression is expressed in alpha · t ^D, the number D a power of power approximate expression alpha · t ^D is -0 Or approximately -0.5
Is calculated as the current open circuit voltage of the battery 13. Therefore, after the discharge of the battery 13 is completed, the open circuit voltage of the battery 13 is measured within a relatively short time. , An asymptote of a power approximation that does not change under the influence of temperature is obtained, and this can be obtained as the current open circuit voltage of the battery 13.

According to the correction coefficient calculating apparatus for detecting the state of charge of a battery according to the present invention,
20. In the calculation of the correction coefficient for detecting the state of charge of the battery according to claim 18 or 19, the open-circuit voltage measured by the open-circuit voltage measuring means 23G during a predetermined time is 2 times.
Since the approximate expression determining means 23H performs regression calculation processing on the arbitrary number of open voltages obtained by this measurement and determines the exponent D of the power approximate expression, the power open approximation α ·
Even if the exponent D of t ^D does not become −0.5, the assumed open circuit voltage when the power approximation is determined a predetermined number of times can be determined as the current open circuit voltage of the battery 13. After the charging and discharging of the battery 13 is completed, the asymptote of the power approximation that does not change under the influence of the temperature is accurately obtained by measuring the open-circuit voltage of the battery 13 measured in a relatively short time, This can be determined as the current open circuit voltage of the battery 13.

Further, according to the correction coefficient calculating apparatus for detecting the state of charge of the battery of the present invention described in claim 21, the charge capacity of the battery of the present invention described in claim 12, 13, 14, 15 or 16 is provided. In the state detection correction coefficient calculation device, as shown in FIG. 2, the elapsed time after the end of the charging or discharging, during a period from a predetermined first time to a predetermined second time, From the open-circuit voltage of the plurality of batteries 13 obtained by measuring a plurality of times by the second open-circuit voltage measuring unit 23K, after charging or discharging is completed, a period from when a first time elapses to when a second time elapses. A predetermined linear approximation expression indicating a correlation between the open-circuit voltage and the elapsed time from the end of charging or discharging is determined by the second approximation expression determining means 23L and is longer than the second time. The third time T And when substituted the elapsed time after the charge or discharge has finished, the solution of the linear approximation determined by the second approximate expression determining means 23L, calculation means 2
The solution of the linear approximation calculated by 3M and calculated by the calculation unit 23M is obtained as the current open circuit voltage of the battery 13 by the open circuit voltage measurement unit 23B.

According to the correction coefficient calculating apparatus for detecting the state of charge of a battery according to the present invention,
22. The battery charge capacity state detection correction coefficient calculating device according to claim 21, wherein the elapsed time after the completion of the charging or discharging is changed from a predetermined first time to a predetermined second time. In the meantime, a plurality of batteries 13 obtained by measuring a plurality of times by the second open-circuit voltage measuring means 23K are obtained.
From the open circuit voltage, t is the elapsed time from the end of charging or discharging, c is the unknown coefficient, and E is the unknown complement, c · t
The linear approximation formula represented by + E is the second approximation formula determination means 23
L.

[0072]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method of calculating a correction coefficient for detecting a state of charge of a battery according to the present invention will be described together with a correction coefficient calculating apparatus for detecting a state of charge of a battery according to the present invention.
Prior to the description with reference to the drawings, measurement of an open circuit voltage corresponding to a terminal voltage in a state of equilibrium of a battery,
The concept of the present invention regarding the measurement of the battery's pure resistance will be described.

First, two ideas on the measurement of the open circuit voltage corresponding to the terminal voltage in the state of equilibrium of the battery will be described.

First, the first concept of the measurement of the open circuit voltage is as follows. Generally, when charging of a battery mounted on a vehicle is completed, the terminal voltage in the open state of the battery increases due to concentration polarization. As time passes, the amount disappears and gradually decreases. For example, as shown in FIG.
It changes so as to approach the open circuit voltage OCV, which is the terminal voltage of the battery at the equilibrium state after time, and such an asymptotic curve is generally expressed by a power equation.

Therefore, the open circuit voltage OCV is unknown at this time.
When the open circuit voltage OCV is assumed as shown in FIG.
′, And the assumed open circuit voltage OCV ′
When subtracted from the voltage V (t), as shown in FIG.
Power approximation α · t asymptotic to ^D Will be represented by
Further, the diffusion phenomenon is represented by a power approximation α · t^D Approximation
The number D is set to be around -0.5.

Then, after the charging of the battery is completed, as shown in FIG. 5, the battery is opened for a predetermined time Ta of, for example, 5 minutes and then for a predetermined time Tb of, for example, 15 minutes. The voltage is measured, and the assumed open circuit voltage OCV 'is subtracted from the measured open circuit voltage to calculate a power approximation α · t ^D.

Generally, the diffusion phenomenon is represented by a power approximation α · t ^D
It is assumed that the power exponent D is approximately -0.5 when approximating by. Change in the open circuit voltage after charging is complete, it is possible to to be due to the voltage change caused by the diffusion of the electrolyte, power approximate expression alpha · t ^D such that the number D is -0.5 should be The assumed open circuit voltage OCV 'obtained at this time can be regarded as the open circuit voltage OCV.

On the other hand, when the discharge of the battery is completed, the terminal voltage in the open state of the battery gradually decreases as the time of the decrease due to the concentration polarization disappears with time, and, for example, after 24 hours. It approaches asymptotically the open circuit voltage OCV which is the terminal voltage in the battery equilibrium state. In the case of discharging, the assumed open circuit voltage OCV 'is expressed by the power approximate expression α.
Since the value is always larger than t ^D, the value obtained by subtracting the assumed open circuit voltage OCV ′ from the measured open circuit voltage is negative. Therefore, the absolute value of the value obtained by subtracting the assumed open circuit voltage OCV ′ from the open circuit voltage is used. To calculate the power approximate expression α · t ^D.

In general, after charging or discharging is completed, the open-circuit voltage of the battery is measured a plurality of times during a predetermined time after a predetermined time has elapsed, and the assumed open-circuit voltage is calculated from the measured open-circuit voltage. Based on the value obtained by subtracting the open circuit voltage, a predetermined power approximate expression having a negative power is determined. The open circuit voltage is updated and repeatedly executed, and the assumed open circuit voltage when the exponent becomes −0.5 may be measured as the open circuit voltage.

If the exponent does not become -0.5 even after the assumed open circuit voltage is updated a predetermined number of times and repeatedly executed, the exponent is reduced by executing the predetermined number of times. It is determined that the value has become approximately -0.5, the assumed open circuit voltage at this time is estimated as the open circuit voltage, and it is possible to eliminate the need to repeat the processing of determining the power approximation formula more than necessary.

The sampling of the open-circuit voltage after a predetermined time Ta of 5 minutes, for example, has elapsed after the charging / discharging is stopped, is caused by the internal resistance and active Includes voltage variations that are not related to the diffusion of the electrolyte, such as overpolarization due to gas polarization and gas generation, and sampling this variation will cause an error, so it should not be included in the data for obtaining the power approximation formula. That's why.

The sampling is performed up to the time Tb not only for the sake of convenience, but also because the change in the voltage with the passage of time becomes small, the estimation accuracy of the open circuit voltage may be reduced depending on the resolution of the measurement. In addition, the influence of the voltage drop due to the dark current of the vehicle increases with time.

As described above, the diffusion phenomenon is expressed by the power approximation α
A specific example that demonstrates that the exponent D is close to -0.5 when approximated by t ^D is shown in FIG. 6 and described. In the power approximation equation determined by using a value obtained by subtracting this from the open-circuit voltage measured after the charging is stopped, the exponent is −0.500, whereas the estimated open-circuit voltage is 12.2 smaller than 12.34V
When the voltage is set to 9 V, the exponent is larger than -0.500 -0.0.
At 452, when the voltage is set to 12.39V which is larger than 12.34V, the exponent becomes -0.559 which is smaller than -0.500. This indicates that when the exponent of the power approximation becomes -0.5, the assumed open circuit voltage becomes equal to the open circuit voltage.

The above is the first concept regarding the measurement of the open circuit voltage. Next, the second concept regarding the measurement of the open circuit voltage will be described.

First, after the charging of the battery is completed, the terminal voltage in the open state of the battery is, for example, asymptotically represented by the exponential equation shown in FIG. The change to approach the open circuit voltage OCV which is the terminal voltage in the equilibrium state is as described above.

As shown in FIG. 7 showing the case after the end of charging, for example, when the temperature is high, the speed of asymptotically approaching the open circuit voltage OCV is faster than when the temperature is low. When the time has elapsed, regardless of the temperature, the terminal voltage decrease acceleration decreases with the lapse of time, and the asymptotic curve is almost linear with respect to the time zone after a certain time has elapsed from the end of charging. The degree is approximated.

Therefore, when a suitable portion of the terminal voltage-time characteristic is linearly approximated after a certain period of time has elapsed from the end of charging, a linear approximation formula V (t) = ct · t + E having an extremely small inclination with respect to the horizontal axis is obtained. Will be represented.

Therefore, after the charging of the battery is completed, as shown in FIG.
The open-circuit voltage of the battery until a predetermined time T2 is measured, and from this measured open-circuit voltage, a linear approximation formula V (t) = c representing the relationship between the open-circuit voltage of the battery and the elapsed time from the end of charging. Calculate t + E.

In general, the change in the open circuit voltage after the end of charge or discharge can be considered to be due to the change in voltage caused by the diffusion of the electrolytic solution, and the diffusion of the electrolytic solution is performed at a low temperature. On the other hand, when the temperature is high, it becomes active. Therefore, the absolute value of c, which is a coefficient indicating the slope of the calculated linear approximation formula V (t) = ct · E + E with respect to the horizontal axis (time axis), is relatively When the temperature is low, the value becomes large, and when the temperature is high, the value becomes small. On the other hand, E, which is a complement indicating the intercept with respect to the vertical axis (voltage axis) of the calculated linear approximation formula V (t) = c · t + E, becomes a large value when the temperature is low after charging, Higher temperatures have smaller values. Conversely, in the case of discharge, the value becomes small when the temperature is low, and becomes large when the temperature is high.

Therefore, this linear approximation formula V (t) = c
In t + E, there is the same time t = T3 at which the open circuit voltage is obtained in the linear approximation formula V (t) = ctt + E, regardless of the values of c and E calculated depending on the temperature. Therefore, the linear approximation formula V (t) = ct · t at this value of t
+ E is the value of the open circuit voltage O
It can be considered as CV.

In the embodiment to be described later, the time T1 at which the sampling of the open-circuit voltage is started is set to 20 minutes after the stop of the charging and discharging, and the time T2 at which the sampling of the open-circuit voltage is ended is set to the stopping time of the charging and discharging. 30 minutes have elapsed since the start of the operation, and a time to be substituted into t of a linear approximation V (t) = c · t + E of the terminal voltage-elapsed time after the end of charge / discharge calculated from the open voltage sampled during the 10 minutes T3 is set to after 1 hour 23 to 24 minutes have elapsed from the stop of charging and discharging. These times can be determined experimentally for each battery specification and can be determined in advance.

The reason why the sampling is performed up to the time T2 is not only for the convenience of stopping the number of samplings to an appropriate number, but also depending on the resolution of the measurement due to the fact that the voltage change becomes small with the passage of time. In addition to the possibility of lowering the estimation accuracy of the circuit voltage,
This is because the influence of the voltage drop due to the dark current of the vehicle increases with time.

[0093] Although two ideas for measuring the open circuit voltage have been described above, the ideas for measuring the pure resistance of the battery will be described next. However, before explaining the concept of measuring the pure resistance, the characteristics of the battery itself will be examined.

By the way, 12V car, 42V car, EV car,
HEV vehicles include starter motors, motor generators,
Loads that require a large current, such as a motor for traveling, are mounted, and examples of voltage-current (VI) characteristics of a battery that supplies power to these loads are shown in FIGS. 9 and 10. Become.

The VI characteristic is, as shown in FIG.
= AI + b can be approximated. However, in consideration of the influence of the non-linear characteristic of the polarization resistance component shown in FIG. As shown in FIG. 10, V = aI ² +
By obtaining a quadratic approximation curve expression of bI + c by the least square method, an approximation curve equation having a high correlation is used.

When a load requiring a large current as described above is driven, constant load discharge is performed at a predetermined large current value corresponding to the maximum power supply value to the load. At this time, the terminal voltage of the battery and the discharge current are periodically measured, and based on actual data indicating the correlation between the terminal voltage and the discharge current, as shown in the graph of FIG. , And a second approximate curve expression M2 of the VI characteristic of the battery during the decrease in the discharge current. Note that the equation described in FIG. 12 is an example of a specific approximate curve equation obtained from actual data. The difference between these two approximate curve expressions M1 and M2 will be analyzed below.

On the other hand, in the case of the approximate curve equation M1, when the discharge starts and the current increases, the polarization resistance component gradually increases based on the polarization resistance component at the time of starting the discharge. Thereafter, when the current reaches the maximum value, the polarization resistance component reaches a peak, and the polarization should be eliminated as the current decreases. However, in practice, the polarization resistance component does not disappear in proportion to the decrease in the current, but the reaction appears later, and therefore the approximate curve equation M2 does not exhibit the same VI characteristic as the increasing direction, As a result, two approximate curve expressions M1 and M2 corresponding to the increase and decrease of the current are obtained.

The above-mentioned two approximate curve expressions M of the VI characteristic
A method of measuring the pure resistance R of the battery using the approximate curves represented by 1 and M2 will be specifically described below with reference to FIGS.

First, as shown in FIG. 13, an arbitrary point A is selected within the range of the actual data on the approximate curve represented by one of the approximate curve expressions M1 and the vertical axis of the approximate curve of the expression M1 is selected. Voltage drop ΔV1 from intercept C1 to point A on the approximate curve
Ask for. The value obtained by dividing ΔV1 by the current I1 at the point A is a combined resistance obtained by adding the value Rpol1 of the polarization resistance component, which is another resistance component other than the pure resistance, to the pure resistance R at that time. That is, R + Rpol1 = ΔV1 / I1.

Similarly, as shown in FIG. 13, an arbitrary point B is selected within the range of actual data on the approximate curve represented by the other of the approximate curve expressions M2, and the vertical axis of the approximate curve of the expression M2 is selected. From the intercept C2 to the point B on the approximate curve
Ask for 2. The value obtained by dividing this ΔV2 by the current I2 at the point B is a combined resistance obtained by adding the value Rpol2 at that time of the polarization resistance component, which is another resistance component other than the pure resistance, to the pure resistance R. That is, R + Rpol2 = ΔV2 / I2.

The difference ΔR between the combined resistance values of the above two points A and B
Is ΔR = R + Rpol1- (R + Rpol2) = Rpol
1−Rpol 2, which is the difference between the polarization resistance components at points A and B.
This is apparent from the fact that the pure resistance R during one discharge does not change.

Note that on the approximate curve represented by the equation M1,
As shown in FIG. 14, there is a point A 'having a value (R + Rpol1') equal to the combined resistance (R + Rpol2) at an arbitrary point B selected on the approximate curve of the equation M2. Further, as shown in FIG. 14, on the approximate curve represented by the equation M2, a value (R + pol) equal to the combined resistance (R + Rpol1) at an arbitrary point A selected on the approximate curve of the equation M1.
There is a point B 'with 2'). That is, a point A 'where R + Rpol1' = R + Rpol2 exists on the approximate curve represented by the equation M1, and a point B 'where R + Rpol1 = R + Rpol2' exists on the approximate curve represented by the equation M2.

In short, assuming that the current and voltage at point A 'are I1' and V1 ', respectively, and the current and voltage at point B' are I2 'and V2', respectively, the coordinates (I1 ', V1') of point A ' And the value of the polarization resistance component of the coordinates (I2, V2) of the point B are equal to each other, and the coordinates (I
1, V1) and the value of the polarization resistance component at point B '(I2', V2 ') are also equal to each other.

First, a method of calculating the current I1 'and the voltage V1' at the point A 'having a value equal to the value of the combined resistance (R + Rpol2) at the point B with reference to the point B will be described below.

[0105] Now, the 'voltage drop to [Delta] V1' from the intercept C1 with respect to the longitudinal axis of the approximate curve represented by Formula 1 this point A and this is ^{ΔV1 '= C1- (a1I1' 2} + b1I1 '+ C1)
= (R + Rpol2) I1 '. When this equation is rearranged,-(a1I1') + B1) = R + Rpol2, and the current I1 ′ at the point A ′ becomes I1 ′ = − (b1 + R + Rpol2) / a1. Note that R + Rpol2 (= R + pol1 ′) = ΔV2 / I2
(= ΔV1 ′ / I1 ′), then I1 ′ = − [b1 + (ΔV2 / I2)] / a1 = − [b1 + (ΔV1 ′ / I1 ′)] / a1. Moreover, the 'voltage V1' points A, as is apparent from the above formula, V1 '= A1I1''since it is + C1, the point A' ² + b1I1 coordinates (I1 ', V1') is determined from the known values Can be

Similarly, on the basis of the point A, the current I2 'and the voltage V2' of the point B 'having a value equal to the resistance value (R + Rpol1) of the point A are also represented by I2' =-[b2 + (. DELTA.V1 / I1). )] / a2 = - by [b2 + (ΔV2 '/ I2' ) ] ^{/ a2 V2 '= a2I2' 2} + b2I2 '+ C2 can be calculated from the known values. Here, ΔV2 ′ is a voltage drop from the intercept C2 to the point B ′ with respect to the vertical axis of the approximate curve represented by Expression 2.

As described above, the coordinates (I
1 ', V1'), the coordinates of point A '(I1', V1 ') and the coordinates of point B (I2, V1') as shown in FIG.
The value R1 of the combined resistance can be obtained by obtaining the slope of the straight line L1 connecting 2). The value R1 of this combined resistance is
It is obtained by dividing the difference (V1'-V2) of the voltage drop caused by the combined resistance composed of the pure resistance and the polarization resistance component Rpol2 by the difference (I1'-I2) of the current flowing at each point. That is, R1 = (V1'-V2) / (I1'-I2).

Similarly, the coordinates of point B '(I2', V
When 2 ′) is determined, as shown in FIG. 15, the slope of the straight line L2 connecting the coordinates (I2 ′, V2 ′) of the point B ′ and the coordinates (I1, V1) of the point A is determined, thereby obtaining the combined resistance. The value R2 is determined. The value R2 of the combined resistance is obtained by dividing the difference (V1-V2 ') of the voltage drop caused by the combined resistance composed of the pure resistance and the polarization resistance component Rpol1 by the difference (I1-I2') of the current flowing at each point. Required by That is, R2 = (V1-V2 ') / (I1-I2').

However, the values R1 and R2 of the combined resistance obtained as described above are obtained by dividing the difference in voltage drop caused by the combined resistance composed of the pure resistance and the polarization resistance component by the difference in the current flowing at each point. It is obtained and does not match the pure resistance. In order to make the slope between the two points coincide with the pure resistance, the difference between the voltage drops excluding the voltage drop caused by the polarization resistance component may be divided by the current difference.

First, the case where the point B is used as a reference will be described. Assuming that the value R1 of the combined resistance is R1 = R1 '+ Rpol2 = R1' + Rpol1 ', the current I1' at the point A 'is added to the resistance R1'. The voltage drop caused by the flow of the current corresponding to the difference between B and the current I2 is caused by the polarization resistance component Rpol1 '(or Rpo1).
l2), the voltage at point A 'may be raised and corrected by the voltage drop caused by the flow of the current corresponding to the difference between the current I1' at point A 'and the current I2 at point B, and the following equation holds. . R1 '(I1'-I2) = [V1' + Rpol1 '(I
1'-I2)]-V2

When this equation is rearranged, R1 ′ (I1′−I2) = (V1′−V2) + Rpol
1 ′ (I1′−I2). Here, Rpol1 '= ΔV1' / I1'-R
1 ′, R1 ′ (I1′−I2) = (V1′−V2) + (ΔV
1 ′ / I1′−R1 ′) × (I1′−I2) 2R1 ′ (I1′−I2) = (V1′−V2) + ΔV
1 ′ / I1 ′ (I1′−I2), and as a result, R1 ′ = [(V1′−V2) + (ΔV1 ′ / I1 ′) ×
(I1'-I2)] / 2 (I1'-I2). Note that (ΔV1 ′ / I1 ′) is (ΔV2
/ I2).

Next, if R2 = R2 '+ Rpol1 = R2' + Rpol2 'in the same manner on the basis of the point A, the resistance R2' is equal to the current I1 of the point A and the current I2 'of the point B'. The voltage drop caused by the flow of the current corresponding to the difference is caused by the polarization resistance component Rpol12 ′ (or Rpol12 ′).
pol1), the voltage at the point B 'may be reduced by the voltage drop caused by the flow of the current corresponding to the difference between the current I1 at the point A and the current I2' at the point B ', and the following equation holds. . R2 '(I1-I2') = V1- [V2'-Rpol
2 '(I1-I2')]

When this equation is arranged, R2 '(I1-I2') = (V1-V2 ') + Rpol
2 '(I1-I2'). Here, Rpol2 '= ΔV2' / I2'-R
2 ′, R2 ′ (I1−I2 ′) = (V1−V2 ′) + (ΔV
2 '/ I2'-R2') (I1-I2 ') 2R2' (I1-I2 ') = (V1-V2') +. DELTA.V
2 ′ / I2 ′ (I1−I2 ′), and as a result, R2 ′ = [(V1−V2 ′) + (ΔV2 ′ / I2 ′)
(I1-I2 ')] / 2 (I1-I2') is obtained. Note that (ΔV2 ′ / I2 ′) is (ΔV1
/ I1).

The two values R1 'obtained as described above
And R2 ′ are based on two points A and B, and have different polarization resistance components (Rpol1 ′ = Rpol2) and (Rpol1).
1 = Rpol2 ′) and the voltage drop Δ1 ′ (ΔV1) from the different intercept C1 and the voltage drop Δ2 ′ (ΔV2) from the intercept C2. Absent. Therefore, the true pure resistance R is obtained by taking the average of the two, R = (R1 '+ R2') / 2.

The concept of measuring the pure resistance of the battery will now be described with reference to FIGS. When a load that requires a large current, such as a starter motor, a motor generator, or a traction motor, mounted on the vehicle to supply power to the vehicle load is operated, the battery supplies the maximum power supply value to the load. Is carried out at a constant load with a predetermined large current value. At this time, the battery terminal voltage and the discharge current are sampled at a cycle of, for example, 1 ms, and are periodically measured, whereby a large number of sets of the battery terminal voltage and the discharge current are obtained.

The latest set of the battery terminal voltage and the discharge current obtained in this manner is stored for a predetermined time, for example, in a memory such as a RAM as rewritable storage means, and is collected by being stored. . This is a voltage-current characteristic showing a correlation between the terminal voltage of the battery and the discharge current during the increase of the discharge current by the least squares method using a set of the terminal voltage and the discharge current stored and stored in the memory. , For example, V
1 (I) = and a1i ² + b1 + first approximate curve equation M1 to C1 represented by a quadratic expression that, voltage for decreasing the discharge current - current characteristic example ^{V2 (I) = a2I 2 +} b2I +
A second approximate curve expression M2 represented by a quadratic expression C2 is obtained.

Next, a first point A is defined on the voltage-current characteristic curve represented by the first approximate curve equation M1, and a first point A is defined on the voltage-current characteristic curve represented by the second approximate curve equation M2. A second point B is defined as follows. At this time, the first point A defined on the voltage-current characteristic curve represented by the first approximate curve equation M1 and the voltage V-current characteristic curve represented by the second approximate curve equation M2 are determined. The second point B is preferably set within a range in which the actual data of the terminal voltage and the discharge current used in obtaining each approximate curve equation exist. By determining in this way, when assuming the supposed points corresponding to the respective points thereafter, the supposed points are not assumed to be located far outside. Preferably, the first point A and the second point B are set on both sides of the point where the polarization resistance component is maximum. With this determination, assumed points are determined on both sides of the maximum point, and thereafter, accuracy in obtaining the pure resistance is improved.

Then, when a second discharge current I2 corresponding to the second point B flows, a second voltage drop ΔV2 is generated, and the pure resistance of the battery and the second polarization resistance component Rpol2
A first assumed point A 'having the same resistance value as the second combined resistance R2 is assumed on the first approximate curve equation M1, and a first discharge current corresponding to the first point A is calculated. A first voltage drop consisting of a pure resistance of a battery and a first polarization resistance component Rpol1 causes a first voltage drop ΔV1 when I1 flows.
A second assumed point B ′ having the same resistance value as the combined resistance R1 is assumed on the second approximate curve equation M2.

When the two assumed points A 'and B' can be assumed, the first slope R1 of the straight line L1 connecting the second point B and the first assumed point A 'is defined as the second discharge current I2. The difference Rp of the voltage drop due to the second polarization resistance component Rpol2, which is caused by the discharge current I1 'at the first assumed point A'.
ol2 (I1'-I2), a first correction slope R1 'excluding the voltage drop due to the second polarization resistance component Rpol2 is obtained, and the first point and the second assumed point are calculated. A second slope R2 of a straight line L2 connecting B ′
The first discharge current I1 and the discharge current I at the second assumed point B '
2 'respectively, the first polarization resistance component R
The voltage drop difference Rpol1 (I1-I
2 ′), the first polarization resistance component Rpo
A second correction slope R2 'excluding the voltage drop due to l1 is obtained.

The first correction slope R thus obtained
By averaging 1 ′ and the second correction slope R2 ′,
The average slope of the first correction slope R1 'and the second correction slope R2' is determined as the pure resistance R of the battery.

An apparatus for performing the above-described method for calculating the correction coefficient used to detect the actual state of the charged capacity of the battery by enabling the above-described embodiment of the present invention will be described below. In the battery state-of-charge measuring device according to the present invention.

FIG. 16 is an explanatory view showing, in partial blocks, a schematic configuration of a battery state-of-charge measuring apparatus according to an embodiment of the present invention to which the method of calculating a correction coefficient for detecting the state of charge of a battery of the present invention is applied. A battery state-of-charge measuring device according to the present embodiment, which is denoted by reference numeral 1 in the drawing, is mounted on a hybrid vehicle having a motor generator 5 in addition to the engine 3.

In this hybrid vehicle, normally, only the output of the engine 3 is transmitted from the drive shaft 7 to the wheels 11 via the differential case 9 to run the vehicle. The motor 5 is configured to function as a motor, and the output of the motor generator 5 is transmitted from the drive shaft 7 to the wheels 11 in addition to the output of the engine 3 to perform assist traveling.

The hybrid vehicle is configured such that the motor generator 5 functions as a generator (generator) at the time of deceleration or braking, and converts the kinetic energy into electric energy to charge the battery 13.

The motor generator 5 is further used as a cell motor for forcibly rotating the flywheel of the engine 3 when the engine 3 is started by turning on a starter switch (not shown). A large current flows in a short time.
This current is called a rush current, and at this time, the motor generator 5 alone consumes more electric power than in a steady state in which a plurality of other electric loads mounted on the hybrid vehicle are simultaneously operating.

In the hybrid vehicle of this embodiment, although the starter switch is off, an accessory switch (not shown), an ignition switch (not shown), and a switch (not shown) of an electric component (load) other than the motor generator 5 are provided. Air conditioner, to be on
When audio equipment, power windows, headlights, room lamps (all not shown), and the like are operating steadily, the discharge current flowing from the battery 13 can be reduced even if a plurality of those electrical components are operating at the same time. For example, 35A
(Ampere).

Conversely, when the accessory switch is turned on, and then the starter switch is turned on, and the motor generator 5 is operated as a starter motor to start the engine 3, even if no other electrical components operate. Even if it does not, a rush current that reaches, for example, 250 A (ampere) flows from the battery 9 instantaneously. Similarly, when the power window switch and the lighting switch are turned on, the power window and the headlight, which are relatively large loads, are not the same as the motor generator 5 used as the cell motor when the power window or the headlight is started or turned on. A large rush current close to that flowing to the generator 5 flows instantaneously.

Therefore, in the battery state-of-charge measuring device 1 of the present embodiment, the discharge current of the battery 13 is changed from the target current value = 35 A (lower limit) to the maximum current value = 250 A.
It is determined whether the constant load discharge for operating the motor generator 5 as a starter motor is being performed and the load discharge similar to the constant load discharge is being performed. It is a guide to distinguish.

When the engine 3 is started by the motor generator 5 by turning on the starter switch,
With the release of the operation of the ignition key (not shown), the starter switch is turned off and the ignition switch and the accessory switch are turned on. Also, when the power window or the headlight is turned on or turned on by turning on the power window switch or the lighting switch while the ignition switch or the accessory switch is turned on, a large rush current close to that flowing to the motor generator 5 is thereby generated. After instantaneously flowing through the power window and the headlight, the discharge current flowing from the battery 13 shifts to a steady current of, for example, less than 35 A (ampere).

Returning to the description of the structure, the battery state-of-charge measuring device 1 of the present embodiment includes a motor generator 5 functioning as a motor for assisted traveling and a cell motor, and the like.
A current sensor 15 for detecting a discharge current I of the battery 13 for electrical components and a charging current I for the battery 13 from the motor generator 5 functioning as a generator.
And a voltage sensor 17 having a resistance of about 1 M ohm connected in parallel with the battery 13 and detecting a terminal voltage V of the battery 13.

Further, the battery state-of-charge measuring device 1 of the present embodiment includes the above-described current sensor 15 and voltage sensor
(Hereinafter abbreviated as "microcomputer") which is taken in after the A / D conversion in the interface circuit (hereinafter abbreviated as "I / F") 21.
23 is further provided.

The microcomputer 23 has a CPU 23
a, a RAM 23b, and a ROM 23c,
The CPU 23a includes a RAM 23b and a ROM 23b.
The I / F 21 and the NVMs 25 and 27 are connected to each other in addition to the switch 23c, and the above-described starter switch, ignition switch and accessory switch (not shown), and switches for electrical components (loads) other than the motor generator 5, such as a power window. A switch, a lighting switch, and the like are further connected.

The RAM 23b has a data area for storing various data and a work area used for various processing operations. The ROM 23c stores a control program for causing the CPU 23a to perform various processing operations. .

When the ignition switch (not shown) is turned off, the microcomputer 23 enters a sleep mode in which only the minimum necessary processing is performed by the dark current supplied from the battery 13, and wakes up when the ignition switch is turned on. It becomes the normal active mode.

The NVM 25 stores and stores the open circuit voltage OCV of the battery 13. The NVM 27 stores the open circuit voltage OCV of the battery 13 at the standard temperature (25 ° C. in this embodiment) at the time of a new battery in which no deterioration occurs. Open-circuit voltage-pure resistance characteristic data (see FIG. 25) indicating the correlation between the resistance and the open-circuit voltage, and the value indicating the state related to the charge capacity of the battery 13 in the static state are represented by the current deterioration degree and the current temperature. Used for correcting the state of the battery 13 to a value related to the actual charge capacity of the battery
And a correction coefficient P having a value corresponding to the difference between the current state and the static state.

Incidentally, at the initial time when the hybrid vehicle is manufactured, the terminal voltage V of the battery 13 separately measured at the time of mounting is previously stored and stored in the NVM 25 as the open circuit voltage OCV.

The current value and the voltage value output from the current sensor 15 and the voltage sensor 17 are sampled and sent to the CPU 2 of the microcomputer 23 via the I / F 21.
The fetched current value and voltage value are stored and stored in the data area (corresponding to the storage means 23bA) of the RAM 23b, from the one before the predetermined period to the latest one. The stored actual data is used to obtain a second-order approximate curve expression of the voltage-current characteristics of the battery 13.

Next, the processing performed by the CPU 23a in accordance with the control program stored in the ROM 23c will be described with reference to the flowcharts of the main routine of FIGS.

When the microcomputer 23 starts up and receives a power supply from the battery 13, the program starts.
First, as shown in FIG. 17, the operation mode of the microcomputer 23 is set to the sleep mode as shown in FIG. 17, and the initial values such as resetting the flag of the flag area provided in the work area of the RAM 23b and clearing the stored value of the timer area are set. The setting is performed (step S1), and the measurement time t of the internal wake-up timer is changed to the wake-up cycle time T.
It is checked whether the number has reached 1 (step S2).

The measurement time t is equal to the wake-up cycle time T1
If it has not reached (N in step S2), the process proceeds to step S7 described below. If it has reached (Y in step S2), the operation mode of the microcomputer 23 is shifted to the active mode (step S3). A circuit voltage update process (step S4) is performed.

The open-circuit voltage updating process in step S4 is based on the first concept of the measurement of the open-circuit voltage described with reference to FIGS. 3 to 6, and FIG. 3, FIG. 7, and FIG. 2 for the measurement of the open circuit voltage described with reference to FIG.
It can be executed by three methods, that is, the first method and the third method different from any of these methods.

First, referring to FIGS. 3 to 6,
In the case where the open circuit voltage updating process of step S4 is performed according to the first concept of the measurement of the open circuit voltage, as shown in the flowchart of the subroutine in FIG. Time Ta
Is determined (step S4a).

If the time has not elapsed, the process waits until the time has elapsed, and if the time has elapsed (step S
4A), the terminal voltage V of the battery 13 is sampled as an open voltage based on the output of the voltage sensor 17 at regular intervals of, for example, 10 seconds, and this is stored and stored in the data area of the RAM 23b (step S4b). And
This sampling is performed, for example, for 1 after the end of charging or discharging.
The operation is continued until the predetermined time Tb of 5 minutes elapses (N in step S4c).

After the time Tb has elapsed (Y in step S4c), the difference between the measured open circuit voltage V (t) and the assumed open circuit voltage OCV ', that is, in the case of charging, the measurement is performed. The value obtained by subtracting the assumed open circuit voltage OCV 'from the measured open circuit voltage V (t). In the case after discharge, the assumed open circuit voltage OCV' based on the measured open circuit voltage V (t).
The absolute value of the value obtained by subtracting is calculated (step S4d), and a power approximation process is performed on the obtained difference value f (t) to determine a predetermined power approximation formula having a negative exponent (step S4e). When the power approximate expression is determined, it is determined whether or not the exponent D of the next determined power approximate expression is equal to -0.5 (step S4f). As a result of this determination, the exponent D becomes-
If it is not 0.5 (N in step S4f), the assumed open circuit voltage OCV 'is updated (step S4f).
g), for the updated assumed open circuit voltage OCV ',
Returning to step S4d, the measured open circuit voltage V
A process of subtracting the assumed open circuit voltage OCV ′ from (t) is performed. When the exponent D becomes -0.5 (Y in step S4f), the assumed open circuit voltage OCV 'when the exponent D becomes -0.5 is obtained as the open circuit voltage OCV and stored in the NVM 25. The stored value of the open circuit voltage OCV of the battery 13 is changed to the assumed open circuit voltage OCV obtained when the exponent D becomes -0.5.
'(Step S4h), and then step S4
And then returns to the main routine of FIG.

Although not described in the flowchart,
When the multiplier of the determined power approximation does not readily reach 0.5, the assumed open circuit voltage OCV 'at the time when the power approximation is determined a predetermined number of times is not shown in the flowchart of FIG. Determined as the circuit voltage OCV,
The value of the open circuit voltage OCV of the battery 13 stored and stored in the NVM 25 is changed to the value of the assumed open circuit voltage OCV ′ obtained at this point in time when the power approximation equation is determined a predetermined number of times. After the updating, the open circuit voltage updating process in step S4 may be ended, and the process may return to the main routine in FIG.

Although not described in the flowchart,
The sampling performed from the time Ta to the time Tb is performed at a constant interval of 10 seconds. However, the sampling is performed at a fixed interval of, for example, three times from the time Ta to the time Tb with the sampling period shortened and sampled at equal intervals. It is also possible to read the same number of open-circuit voltages as at the time and put the microcomputer in a sleep state during a period in which no sampling is performed.

Here, the method of determining the power approximation equation in step S4e will be described below.

The power approximation y = α · x ^D can be expressed as: ln (y) = ln (α) + D · ln (x). Now, ln (y) = Y, ln (α)
= A, ln (x) = X, a linear equation Y = A + D.X is obtained. A and D are obtained as follows by regression analysis.

Assuming that the difference between the approximate expression and the actual data is ε, Yi = A + D · Xi + εi (i = 1, 2,..., N) can be obtained. Since A and D that minimize the sum of εi (i = 1, 2,..., n) can be obtained,
In the case of the least square method, εi ² (i = 1, 2,...,
A and D that minimize the sum of n) are obtained.

Specifically, it is expressed by the following equation. δΣεi / δA = 0 δΣεi / δD = 0 By solving the simultaneous equations, by which ΣYi-DΣXi-ΣA = 0 ΣXiYi -DΣXi 2 -AΣXi = 0, D = (ΣXiYi-nXaYa) / (ΣXi 2 -nXa
² ) A = Ya-DXa

Xi is X-axis data, Yi is Y-axis data, n is the number of data, Xa is the average value of Xi, and Ya is the average value of Yi. As described above, since A = ln (α), the power approximate expression y = α · x ^D can be obtained from α = e ^A.

Next, how to update the assumed open circuit voltage OCV 'in step S4g will be described with reference to FIG.

[0153]

[Table 1]

When estimating the open circuit voltage after the end of charge / discharge, the assumed open circuit voltage OCV 'is updated by a method generally called a binary tree search method. First, as shown in FIG. 20, the assumed open circuit voltage OCV ′ is, for example, the upper assumed open circuit voltage V _(Tb) , the lower assumed open circuit voltage 0, and the intermediate assumed open circuit voltage V _(Tb) / 2. A power approximation is performed for the case.

D obtained from each approximation
(V _(Tb) ), D (0) and D (V _(Tb) / 2) are compared with each other. If D of the intermediate assumed open circuit voltage is equal to or not equal to -0.5,- A comparison is made as to whether it is larger or smaller than 0.5. When D of the intermediate assumed open circuit voltage is not -0.5, the range including data of -0.5 is included,
In the example of Table 1, the assumed open-circuit voltage (V) obtained by dividing the range between the intermediate assumed open-circuit voltage and the upper limit assumed open-circuit voltage into two.
D of _(Tb) + V _(Tb) / 2) / 2 is calculated, and the comparison operation is repeated until D = -0.5. Table 1 shows a specific example. In the example of Table 1, even when the number of searches is other than 1, the exponent D of each of the lower limit, the middle, and the upper limit is calculated and obtained. However, in the second and subsequent searches, the calculation of the exponent D only needs to be the middle.

If the exponent does not become -0.5 even when the assumed open circuit voltage is updated and repeatedly executed, the lower limit assumed open circuit voltage and the upper limit assumed open circuit voltage are set to the third decimal place. It is determined that the exponent has become approximately -0.5 when the numerical value of is no longer about 1, and the assumed open circuit voltage OCV ′ at this time is calculated as the open circuit voltage OCV, and the power approximation formula is more than necessary. Can be eliminated.

The first upper limit assumed open circuit voltage is set to V _(Tb) because the open circuit voltage OCV never becomes higher than V _(Tb) . The lower limit assumed open circuit voltage may be the open circuit voltage OCV at the time of completion of discharge (capacity 0%). However, if overdischarge is performed, the open circuit voltage at the time of completion of discharge (capacity 0%) is reduced. Initial value is 0V because it may turn
I have to.

Next, in the case where the open circuit voltage updating process of step S4 is executed according to the second concept of the measurement of the open circuit voltage described with reference to FIG. 3, FIG. 7, and FIG. As shown in the flowchart of the subroutine in FIG. 21, it is determined whether a predetermined time T1 of, for example, 20 minutes has elapsed from the end of charging or discharging (Step S).
4A).

If the time has not elapsed, the process waits until the time has elapsed, and if the time has elapsed (step S
4A, Y), the terminal voltage of the battery is sampled as an open voltage based on the output of the voltage sensor 17 at regular intervals of, for example, 10 seconds, and this is stored and stored in the data area of the RAM 23b (step S4B). This sampling is continued until a predetermined time T2 of, for example, 30 minutes elapses from the end of charging or discharging (N in step S4C).

When the time T2 has elapsed (Y in step S4C), a linear approximation process is performed on the measured open circuit voltage V (t) to determine a linear approximation formula (step S4).
D). When the straight-line approximation equation is determined, a solution of the straight-line approximation equation is obtained by substituting a predetermined time T3 of, for example, 1 hour 23 to 24 for the variable t of the next determined straight-line approximation equation (step S4).
E), this solution is found as open circuit voltage OCV and NVM
After the value of the open circuit voltage OCV of the battery 13 stored and stored in the battery 25 is updated to the value of the solution of the linear approximation equation obtained here (step S4F), the open circuit voltage update processing in step S4 is completed. Then, the process returns to the main routine of FIG.

Although not described in the flowchart,
Sampling performed from time T1 to time T2 is performed at a fixed interval of 10 seconds. However, sampling is performed at a fixed interval of, for example, three times from time T1 to time T2 with a reduced sampling period, and sampled at equal intervals. It is also possible to read the same number of open-circuit voltages as at the time and put the microcomputer in a sleep state during a period in which no sampling is performed.

Subsequently, the first concept regarding the measurement of the open-circuit voltage described with reference to FIGS. 3 to 6 and the open-circuit voltage described with reference to FIGS. 3, 7 and 8 will be described. FIG. 22 is a flowchart of a subroutine in which the open circuit voltage updating process of step S4 is performed according to the third method of measuring the open circuit voltage, which is different from any of the second method of measuring the circuit voltage. As shown by, it is confirmed whether or not the predetermined time Th required for eliminating polarization from the maximum polarization occurrence state has been exceeded from the end of charge or discharge (step S4s).

Here, the continuous non-energization time T is equal to the predetermined time Th.
Does not exceed (N in step S4s), the open circuit voltage updating process in step S4 is terminated, and the process returns to the main routine of FIG.
Y), the A / D conversion value of the terminal voltage V of the battery 13 detected by the voltage sensor 17 is obtained from the I / F 21 (step S4t).

Subsequently, the open circuit voltage OCV of the battery 13 stored and stored in the NVM 25 is changed to the value in step S4t.
Is updated to the A / D converted value of the terminal voltage V of the battery 13 obtained at step S4v (step S4v), and the flag F1 in the equilibrium state flag area of the RAM 23b is set to "1" (step S4w). And returns to the main routine of FIG.

When the open circuit voltage updating process in step S4 is completed, as shown in FIG. 17, the measurement time t of the internal wake-up timer is reset (step S5), and the operation mode of the microcomputer 23 is set to sleep. After returning to the mode (step S6), the process returns to step S2.

On the other hand, when the measured time t has not reached the wake-up cycle time T1 in step S2 (N)
In step S7, the process proceeds to step S7 to check whether all switches are off (step S7).
7).

If all switches are off (Y in step S7), the process returns to step S2.
When any of the switches is not turned off (N in step S7), the operation mode of the microcomputer 23 is shifted to the active mode (step S8), and the open circuit voltage of the battery 13 stored and stored in the NVM 25 is stored. OCV
Is converted into an electric quantity represented by ampere x time (Ah) to obtain a static initial electric quantity (Ah) immediately before the start of charging and discharging, and the electric quantity stored and stored in the data area of the RAM 23b is The initial amount of electricity (Ah) obtained here is updated (step S9).

In obtaining the static initial amount of electricity immediately before the start of charging and discharging in step S9, the specific gravity of the electrolyte of the battery 13 and the open circuit voltage OCV, which are generally said to have a substantially linear correlation, are obtained. The linear correlation as shown in the graph of FIG. 23 derived from the relationship between the specific gravity of the electrolyte of the battery 13 and the static electricity amount (Ah), which is also said to have a linear correlation, The relationship between the static electricity amount (Ah) of the battery 13 and the open circuit voltage OCV, which should hold, is used. Specifically, the value of the open circuit voltage OCV of the linear characteristic equation shown in the graph of FIG.
By substituting the value of the open circuit voltage OCV of the battery 13 stored and stored in 25, a static initial amount of electricity immediately before the start of charging and discharging is obtained.

In step S9, a static initial electric quantity immediately before the start of charge / discharge is obtained, and the value of the electric quantity (Ah) stored in the data area of the RAM 23b and stored is updated. Battery 13 detected by
And the A / D conversion value of the charging / discharging current I of the battery 13 and the A / D conversion value of the terminal voltage V of the battery 13 detected by the voltage sensor 17.
A real data collection process is performed in which data is collected via the I / F 21 and stored in the data area of the RAM 23b (step S10). This step S
The actual data collection process in 10 is always performed continuously.

Thereafter, it is confirmed whether or not the switch that is not turned off is a starter switch (not shown) (step S11).
If the switch is not a starter switch (N in step S11), the switch that is not turned off is replaced by another load that flows a large rush current similar to the motor generator 5 that is a constant load. It is checked whether or not the switch is a high-current switch such as a power window switch or a lighting switch for starting discharge to a certain power window motor or headlight (step S12).

If the switch that is not turned off is not a large current switch (N in step S12), the process proceeds to step S15 described later. If the switch is not a large current switch (Y in step S12), it is not turned off in step S11. When the switch is a starter switch (not shown) (Y), the process proceeds to step S13 to perform a pure resistance calculation process.

In the pure resistance calculation process in step S13, as shown in the flowchart of the subroutine in FIG. 24, the discharge current I collected in step S10 is calculated.
The actual data for the latest predetermined time between the terminal voltage V and the terminal voltage V is analyzed, and whether or not the data is appropriate for obtaining a quadratic approximate curve equation of the voltage-current characteristic by applying the least square method is determined. An analysis process is performed to analyze whether a constant load discharge is performed from the battery 13 with a predetermined large current value (step S13a).

Next, as a result of the analysis in step S13a, it is confirmed whether or not the data suitable for obtaining the second-order approximate curve expression of the voltage-current characteristics has been collected (step S13a).
13b) When no suitable items are collected (N)
Terminates the pure resistance characteristic calculation process and returns to the main routine of FIG. 17. If a proper one is collected (Y), for example, the voltage-current characteristic of the battery 13 during the increase of the discharge current, for example, V1 (I) = a1I ² + b1 +
A first approximation curve equation M1 represented by a quadratic expression that C1, the voltage of the battery 13 during the reduction of the discharge current - current characteristic, for example, ^{V2 (I) = a2I 2 +} b2I + C2 becomes 2
An approximate curve expression calculation process for obtaining a second approximate curve expression M2 represented by the following equation is executed (step S13c).

After the two approximate curve expressions M1 and M2 are obtained by the approximate curve expression calculation processing in step S13c,
Next, an arithmetic process for obtaining the pure resistance of the battery 13 is executed (Step S13d). In the calculation processing in step S13d, the pure resistance and the first polarization of the battery 13 cause a voltage drop when a discharge current corresponding to a point defined on the voltage-current characteristic curve represented by the approximate curve equation M2 flows. A first assumed point having the same resistance value as the combined resistance composed of the resistance components is assumed on the voltage-current characteristic curve represented by the first approximate curve equation M1. Further, it consists of a battery's pure resistance and a second polarization resistance component that cause a voltage drop when a discharge current corresponding to a point defined on the voltage-current characteristic curve represented by the first approximate curve equation M1 flows. A second assumed point having the same resistance value as the combined resistance is assumed on the voltage-current characteristic curve represented by the second approximate curve equation M2.

In the calculation processing in step S13d,
Further, the first slope of a straight line connecting the point defined on the voltage-current characteristic curve represented by the approximate curve equation M2 and the first assumed point is represented by the voltage-current represented by the second approximate curve equation. The second polarization resistance component is corrected by the difference between the voltage drop due to the second polarization resistance component, which is caused by the discharge current corresponding to the point defined on the characteristic curve and the discharge current at the second assumed point. A first correction slope excluding the voltage drop due to the above is obtained.

In the calculation processing in step S13d,
Further, a second straight line connecting a point defined on the voltage-current characteristic curve represented by the approximate curve equation M1 and the second assumed point is used.
Of the first polarization resistance component generated by the discharge current corresponding to the point defined on the voltage-current characteristic curve represented by the first approximate curve equation and the discharge current at the second assumed point, respectively. After correcting for the difference in voltage drop due to
A second correction slope excluding the voltage drop due to the first polarization resistance component is obtained. Then, the first correction slope and the second correction slope obtained in step S13d are averaged, and the average slope of these two correction slopes is calculated by the battery 1.
17 is stored as a pure resistance in the data area of the RAM 23b in order to use the obtained pure resistance for various purposes (step S13e). Return to routine.

When the pure resistance calculation processing in step S13 is completed, the process proceeds to step S14 as shown in FIG.
A correction coefficient calculation process is performed.

In the correction coefficient calculation processing in step S14, the open circuit voltage-pure resistance characteristic stored and stored in the NVM 27, which is indicated by a solid line in the graph of FIG.
The value of the pure resistance of the battery 13 in the static state corresponding to the current open circuit voltage OCV of the battery 13 is determined, and the value of the pure resistance of the battery 13 in the static state and R
A correction coefficient P is obtained by dividing the difference between the current pure resistance value of the battery 13 stored and stored in the data area of the AM 23b by the pure resistance value of the battery 13 in the static state, The value of the correction coefficient P stored and stored in the NVM 27 is updated to the value of the correction coefficient P determined here.

When the correction coefficient calculation processing in step S14 is completed, the process proceeds to step S15 as in the case where the switch that is not turned off in step S12 is not a high current switch (N), and the battery 13 for the charge / discharge circuit (not shown) is used. Of the battery 13 is checked, or the sign of the charge / discharge current I of the battery 13 collected in step S10 is checked to determine whether or not the battery 13 is in a charged state.

If it is determined in step S15 that the battery 13 is not in the charged state (N), the process proceeds to step S17 described later. If it is determined that the battery 13 is in the charged state (Y), as shown in FIG. Then, a charging open circuit voltage calculation process is executed (step S16).

In the charging open circuit voltage calculation process in step S16, as shown in the flowchart of the subroutine in FIG. 26, the charging current I _CHG and the terminal voltage V of the battery 13 collected in step S10 are averaged by an appropriate number. Then, the average value of the terminal voltage V and the charging current I _CHG of the battery 13 is obtained (step S16a), and it is confirmed whether the obtained average value of the terminal voltage V is in a stable state (step S16).
16b).

Incidentally, whether or not the average value of the terminal voltage V is in a stable state in step S16b is determined as follows.
This means checking whether the terminal voltage V of the battery 13 has converged to a preset charging voltage value.

The terminal voltage V of the battery 13 is
When converging to the set charging voltage value, the graph of FIG.
Occurs in the battery 13 in the area (a) in FIG.
Current I of the battery 13 as the charging-side polarization progresses
_CHGChanges occur in about 5 to 10 seconds,
The terminal voltage V in the region (a) in FIG.
While the charging current I of the battery 13 is substantially constant._CHG
It takes about 10 minutes for the average value of
Thus, the charging current I of the battery 13 _CHGFlat
The average value decreases significantly.

For this reason, it is confirmed whether or not the average value of the terminal voltage V in the step S16b is in a stable state by confirming whether or not the rate of decrease of the average value of the charging current I _CHG is significantly lower than a predetermined value. Can be confirmed.

When the terminal voltage V of the battery 13 converges to a preset charging voltage value, the charging current I of the battery 13 depends on the charging voltage value applied to the battery 13.
_CHG is Sadamari, battery 1 in accordance with the charging current I _CHG
Since the traveling speed toward the saturation of the charging-side polarization generated in 3 is determined, the charging current I _CHG of the battery 13 in the region (A) in FIG. The time required for the change, that is, the elapsed time from the start of charging to the convergence to the charging voltage value is almost uniquely determined according to the charging voltage value.

Therefore, the required elapsed time from the start of charging corresponding to the preset charging voltage value to the convergence of the charging voltage value is set in advance in the ROM 23c or the like, and the required elapsed time has elapsed from the start of charging. By confirming whether or not the average value of the terminal voltage V in step S16b is in a stable state, it can be confirmed.

As described above, it is determined whether or not the average value of the terminal voltage V is in a stable state in step S16b. As a result, if the average value of the terminal voltage V is not in a stable state (step S16b) N), the charging open circuit voltage calculation processing is terminated, and the process returns to the main routine of FIG. 18. If the circuit is in a stable state (Y in step S16b),
The average value of the terminal voltage V determined in step S16a, the preset charge voltage value, i.e., the position and set the charging voltage value V _T, the charging current I obtained in step S16a
The average value of _CHG is positioned as the boundary between the region (a) and the region (a) in FIG. 27, that is, the charging current value I _CHG0 at the start of the voltage stable region (step S16).
c).

Subsequently, the internal resistance R + Rpol of the battery 13 at this time, ie, at the start of the voltage stable region,
(Synthetic resistance obtained by adding the value Rpol of the pure resistance R and the polarization resistance component as the other resistance component at that time) (step S16d).

The battery 1 in step S16d
The specific method of obtaining the internal resistance R + Rpol and the concept thereof are as follows.

First, when the battery 13 has the set charging voltage value V _T
The terminal voltage V of the battery 13 actually measured using the voltage sensor 17 in a state where the battery 13 is charged at a constant voltage by
As confirmed in step S16b, the set charging voltage value V _T
And that the stable state has been reached, it can be assumed that the charging-side polarization generated in the battery 13 by the constant-voltage charging stops increasing and the charging-side polarization is saturated.

By the time the charge-side polarization reaches the start of the saturated voltage stable region, only about 5 to 10 seconds have elapsed as described above. Since the charging-side polarization of the battery 13 has reached the maximum value, the energy given to the battery 13 by the charging up to the start of the voltage stable region is almost converted to the charging-side polarization, Battery 13
It can be assumed that the internal electromotive force E ₀ has not increased at all from the start of charging until the start of this voltage stable region.

Since the open circuit voltage OCV, which is the terminal voltage V in a state where the battery 13 is in an equilibrium state, is the internal electromotive force E ₀ of the battery 13 in the first place. Assuming that the internal electromotive force E ₀ of the battery 13 has not increased at all until the start time, the value is the latest value of the open circuit voltage OCV of the battery 13 obtained in step S4.

Therefore, based on this point, the voltage stable region
Expression of the state of the battery 13 at the start of
Set charging voltage at the terminal voltage V of the battery 13
Value V _TFrom the internal electromotive force E of the battery 13₀Minus
Is stable to the internal resistance R + Rpol of the battery 13
Charge current value I at the start of the region_CHG0Multiplied by
Should be equal to V_T-E₀= (R + Rpol) × I_CHG0

Therefore, the internal resistance R +
Rpol is expressed by the following equation: (R + Rpol) = (V _T −E ₀ ) / I _CHG0 (where E
₀ = OCV = Vn ').

When the internal resistance R + Rpol of the battery 13 is obtained in step S16d in this manner, next, after the start of the voltage stable region collected in step S10, that is, the region (a) in FIG. using the value I _CHG1 of the charging current I _CHG of the battery 13 in, it calculates the open-circuit voltage OCV _CHG static battery 13 during charging, stored in NVM25, the open circuit voltage OCV of the stored battery 13 The value is updated to the value of the open circuit voltage OCV _CHG calculated here (step S16e).

The specific contents of the calculation of the open circuit voltage OCV _CHG of the static battery 13 being charged in this step S16e and the concept thereof are as follows.

First, at the time of this step S16e,
Since the start point of the voltage stable region where the charging-side polarization is saturated has passed, the internal resistance R + Rpol of the battery 13 should not change. Then, (a) in FIG.
The decrease in the charge current I _CHG of the battery 13 in the region of
The increase in the internal electromotive force E ₀ of should cause all of them.

Therefore, assuming that the internal electromotive force of the battery 13 after the increase is E ₀ ′, the following equation is obtained: V _T −E ₀ ′ = (R + Rpol) × I _CHG1 (where E ₀
＞> E ₀ ), and the above equation showing the state of the battery 13 at the start of the voltage stable region, V _T −E ₀ = (R + Rpol) × I _CHG0 , When the amount of decrease I _CHG of the charging current I _CHG of the battery 13 after the start of the _calculation is expressed as I _CHG0 −I _CHG1 , E ₀ ′ −E ₀ = (R + Rpol) × (I _CHG0 −I _CHG1 ).

Thus, the internal electromotive force E ₀ ′ of the battery 13 after the start of the voltage stable region is the open circuit voltage OCV ′ of the battery 13 after the start of the voltage stable region, and as described above, Battery 13 at start
Of the internal electromotive force E _0, when it comes to the value of the open circuit voltage OCV of the battery 13 before starting charging determined in step S2, the following _{equation, E 0 '= E 0 +} (R + Rpol) × (I CHG0 -I _CHG1 ), the open circuit voltage OCV _CHG of the static battery 13 being charged can be obtained.

After the calculation of the open circuit voltage OCV _CHG of the battery 13 being charged in step S16e and the updating of the open circuit voltage OCV of the battery 13 stored and stored in the NVM 25 are completed as described above. FIG. 23
The battery 1 stored and stored in the NVM 25 as the value of the open circuit voltage OCV of the linear characteristic equation shown in the graph of FIG.
3 to determine the static electricity amount (Ah) of the battery 13 being charged, and store the current electricity amount of the battery 13 stored and stored in the data area of the RAM 23b, by substituting the value of the open circuit voltage OCV of FIG. After updating to the electric quantity (Ah) obtained here, the open circuit voltage calculation process at the time of charging is ended, and the process returns to the main routine of FIG.

Further, as shown in FIG.
In step S17, in which it is determined in step S5 that the battery 13 is not in the charged state (N), the process proceeds to step S10.
The current integration process is performed using the discharge current I of the battery 13 collected in step (1). That is, in the current integration process of step S17, the integrated current value obtained by multiplying the measured discharge current I by the sampling cycle time of the discharge current I is stored and stored in the data area of the RAM 23b. , And the value of the current electricity amount of the battery 13 stored and stored in the data area of the RAM 23b is updated to the value after the subtraction.

After the current integration processing in step S17, the battery stored and stored in the data area of the RAM 23b as the value of the electric quantity (Ah) of the linear characteristic equation shown in the graph of FIG. 13 to determine the static open circuit voltage OCV of the battery 13 during discharging, and store and store the value of the open circuit voltage OCV of the battery 13 in the NVM 25. The calculated value of the open circuit voltage OCV is updated (step S18).

After performing the charging open circuit voltage calculation process in step S16, calculating the static open circuit voltage OCV of the battery 13 in step S18, and setting the NVM 25
The open circuit voltage OC of the battery 13 stored and stored in
When the update of the value of V is completed, a charge state calculation process for obtaining a static charge state SOC of the corresponding battery 13 from the value of the open circuit voltage OCV of the battery 13 stored and stored in the NVM 25 is performed. (Step S19).

The state of charge SO in step S19
C is calculated by a voltage ratio, SOC = {(OCV−Ve) / (Vs−Ve)} × 100 (%) or a power ratio, SOC = {[(OCV + Ve) / 2] × [(OCV−Ve) / (Vs−Ve)] × Ah｝ / {[(Vs + Ve) / 2] × Ah} × 100 (%) = {(OCV ² −Ve ² ) / (Vs ² −Ve ² ) ｝ × 100 (%) (where Vs is the open circuit voltage at the time of full charge, Ve is the open circuit voltage at the end of discharge) and stored in the NVM 25 and stored in the NVM 25 This is performed by substituting the value of OCV.

When the static state of charge SOC of the battery 13 is obtained in step S19, the correction coefficient P stored and stored in the NVM 27 is multiplied by the value of the state of charge SOC obtained in step S19 to obtain a static state. The value of the state of charge SOC of the battery 13 in the state
After performing a state-of-charge correction process for correcting the actual state-of-charge SOC of the battery 13 in accordance with the current state of the condition that changes the state of charge, such as the degree of deterioration and temperature of the battery 3, (step S20) It is determined whether or not the switch is turned off (step S21).

If any switch is not off (N in step S19), the process returns to step S10, and if all switches are off (step S19).
19), the current time measured by the internal time counter is stored in the energization end time area of the RAM 23b, and the measurement time t of the internal wake-up timer is reset (step S20). After setting the mode to the sleep mode (step S21), it is confirmed whether or not the power supply from the battery 13 has been cut off (step S22).

If the power supply from the battery 13 has not been cut off (N in step S22), the process returns to step S2, and if cut off (Y in step S22), the termination processing is performed (step S23). , A series of processing ends.

As is clear from the above description, in the battery state-of-charge measuring apparatus 1 of the present embodiment, the open-circuit voltage updating process of step S4 is executed according to the above-described first concept of the measurement of the open-circuit voltage. If you do
Step S4b in the flowchart of FIG. 19 is a process for the open-circuit voltage measuring means in the claims, step S4e is a process corresponding to the approximate expression determining means in the claims, and steps S4f and S4g are the claims. The processing corresponds to the arithmetic control means in the section.

When the open circuit voltage updating process of step S4 is executed according to the above-described second concept of measuring the open circuit voltage, step S4B in the flowchart of FIG. Step S4D corresponds to the approximation formula determining means in the claims, and step S4E corresponds to the calculating means in the claims.

Further, when the open circuit voltage updating process of step S4 is executed according to the third concept of the measurement of the open circuit voltage described above, step S4B in the flowchart of FIG. Step S4D corresponds to the approximation formula determining means in the claims, and step S4E corresponds to the calculating means in the claims.

In the battery state-of-charge measuring apparatus 1 of the present embodiment, step S13 in the flowchart of FIG. 17 corresponds to processing corresponding to the pure resistance measuring means 23A in the claims. S4 is
In addition to the processing corresponding to the open circuit voltage measuring means 23B in the claims, step S14 in FIG. 17 includes the static pure resistance value finding means 23C and the arithmetic means 23D in the claims.
Is a process corresponding to.

Further, in the battery state-of-charge measuring apparatus 1 of the present embodiment, step S13c in the flowchart of FIG. 24 is a process corresponding to the approximate curve equation calculating means 23E in the claims. S13
d is a process corresponding to the second calculating means 23F in the claims.

Further, in the battery state-of-charge measuring device 1 of this embodiment, step S4b in the flowchart of FIG. 19 is a process corresponding to the open-circuit voltage measuring means 23G in the claims, and step S4e in FIG. Are the processing corresponding to the approximate expression determining means 23H in the claims, and the steps S4f and S4 in FIG.
4g is processing corresponding to the arithmetic control means 23J in the claims.

Further, in the battery state-of-charge measuring device 1 of the present embodiment, step S4B in the flowchart of FIG. 21 is a process corresponding to the second open-circuit voltage measuring means 23K in the claims. Step S4D
Is a process corresponding to the second approximate expression determining means 23L in the claims, and step S4E in FIG.
This processing corresponds to the calculation means 23M in the claims.

Next, the operation (operation) of the battery capacity computing device 1 of the present embodiment configured as described above will be described.

First, when electric components (loads) other than the motor generator 5 of the hybrid vehicle are operating or the motor generator 5 is operating so as to function as a motor, the battery 13 is discharging. When the generator 5 is operating to function as a generator, the battery 13 is being charged. The charge / discharge of the battery can be detected by taking in the output of the current sensor 15, and the end of the charge / discharge
Can be detected by the fact that the output is zero.

When the end of charging / discharging is detected based on the output of the current sensor 15, the measurement of the open circuit voltage OCV of the battery 13 for updating to the latest value is executed by the following three methods.

First, in the first method, when the end of charging / discharging is detected, the output of the voltage sensor 17 is fetched from the time when a certain time Ta has elapsed to the time Tb, thereby obtaining the terminal voltage of the battery. Is periodically measured as an open voltage, and these voltage values and the elapsed time from the end of charge / discharge are stored, stored, and collected in the data area of the RAM 23b. The assumed open circuit voltage E is subtracted from the collected terminal voltage V (t), and the power approximate expression is determined by applying the least square method from the value obtained by the subtraction. The determined cumulative approximate expression α
t ^D stated Ki number D, it is determined whether it is -0.5, should be in when the number D is not set to -0.5, again similar to update the assumed open circuit voltage OCV' a new one Processing is performed to determine the power approximate expression α · t ^D. The above operation is repeated until the exponent D becomes -0.5 or substantially -0.5, and when either of them is satisfied, the assumed open circuit voltage OCV 'at that time is changed to the open circuit voltage OCV. The open circuit voltage OCV of the battery 13 stored and stored in the NVM 25 is updated. It should be noted that confirmation that the value has become approximately -0.5 can be performed when the number of determinations of the power approximation becomes a predetermined number or when the assumed open circuit voltage range becomes equal to or less than a predetermined range. .

[0219] The first open circuit voltage OCV measured by the method described above, since a asymptote power approximate expression alpha · t ^D, even if power approximate expression alpha · t ^D is changed by temperature and time Even if Ta and Tb are different, they do not move, so that temperature correction is not required at all, and even if the characteristics of the battery 13 are slightly different, the present invention can be applied as it is. In addition, if the charging / discharging current does not flow during the period from Ta to Tb from the end of charging / discharging, the open circuit voltage OCV can be measured each time, and the open circuit voltage OCV can be measured.
Can be measured more frequently.

In the above description, it is assumed that the asymptote of the power approximation does not change depending on the temperature. This is because although the open circuit voltage OCV is strictly changed depending on temperature, it is negligible.

Next, in the second method, when the end of charging / discharging is detected based on the output of the current sensor 15, the voltage sensor 17 is switched from the time when a certain time T1 elapses to the time T2 elapses. By capturing the output of
Periodically measure the terminal voltage of the battery as the open-circuit voltage,
These voltage values and the time elapsed from the end of charge / discharge are RA
It is stored, stored and collected in the data area of M23b. Applying the least squares method from the collected terminal voltage V (t),
V (t) = c · t + E The coefficients c and E in the battery's linear terminal voltage−elapsed time after charging / discharging characteristic equation are obtained, and this equation V (t) = c · t + E is obtained by the above sampling. Between the terminal voltage of the battery and the elapsed time after the end of charge / discharge. Then, a solution obtained by substituting a time T3 indicating a certain time after the end of charging / discharging into this equation is used as an open circuit voltage OCV, and NVM is obtained.
25, the open circuit voltage OCV of the battery 13 is updated.

As described above, the open circuit voltage OCV measured by the second method is represented by a linear approximation formula V (t) = ct · E + E
Is a solution obtained by substituting the time t = T3 such that is almost the same value, so that even if the coefficients c and E change depending on the temperature, it does not move. Can be applied as is even if the characteristics are slightly different. In addition, if the charging / discharging current does not flow during the time T1 to T2 from the end of charging / discharging, the open circuit voltage OCV can be measured each time,
The frequency at which the open circuit voltage OCV can be measured can be increased.

In the above description, it is assumed that the solution obtained by substituting the time t = T3 into the linear approximation equation does not change depending on the temperature.
This is because t = T3 that does not depend on the temperature is determined in advance.

Subsequently, in the third method, the current sensor 15
When the end of charging / discharging is detected by the output of the battery 13, the charging / discharging of the battery 13 last time is continued unless the charging / discharging of the battery 13 exceeds the predetermined time Th required for eliminating polarization from the maximum polarization generation state. It is assumed that the voltage fluctuation (voltage rise or voltage drop) due to the polarization generated at the time of discharging is completely eliminated and the equilibrium state is reached.
The open circuit voltage OC of the battery 13 stored and stored in
V is updated to the terminal voltage V of the battery 13 detected before the start of the constant load discharge.

Next, when one of the switches of the hybrid vehicle is turned on to put the battery 13 in a chargeable / dischargeable state, the battery 13 is first used to determine the charge state by the current integration method during the discharge of the battery 13. NV
From the value of the latest open circuit voltage OCV of the battery 13 stored and stored in M25, the current initial electricity amount of the battery 13 is calculated, and the charge / discharge current I of the battery 13 by the current sensor 15 and the voltage sensor 17 is calculated. And the periodic and continuous measurement of the terminal voltage V is started.

The turned on switch is, for example, 2
A battery 1 is supplied to the motor generator 5 which functions as a cell motor with a constant load discharge exceeding 50 A (ampere).
The battery 13 starts discharging to a starter switch to be performed by the power supply 3 and to a power window motor and headlights, which are other loads that flow a large rush current similar to the motor generator 5 that is a constant load.
If the switch is a large current switch such as a power window switch or a lighting switch, the battery
Are periodically collected as a pair, the actual data for the latest predetermined time between the collected discharge current I and the terminal voltage V is analyzed, and the voltage-current A determination is made as to whether it is appropriate to determine a quadratic approximate curve equation for the characteristic.

Then, when it is determined that the data is appropriate as a result of the analysis, the voltage-current characteristics of the battery 13 during the increase of the discharge current, for example, V1 ( a first approximation curve equation M1 represented by a quadratic expression that ^{I) = a1I 2 + b1 +} C1, the voltage of the battery 13 during the reduction of the discharge current - current characteristic, for example, ^{V2 (I) = a2I 2 +} b2I + C2 becomes secondary A second approximate curve equation M2 represented by the following equation is obtained.

Further, the first approximate curve equation M1 and the second approximate curve equation M2, the first assumed point corresponding to the second approximate curve equation M2, and the second approximate curve equation M1 according to the first approximate curve equation M1. 2
The first correction slope and the second correction slope are respectively obtained from the assumed point, and the current pure resistance of the battery 13 is obtained from the averaging of the first correction slope and the second correction slope.

When the current pure resistance of the battery 13 is obtained in this way, the NV resistance is calculated using the open circuit voltage-pure resistance characteristic of the battery 13 stored and stored in the NVM 27.
The value of the pure resistance of the battery 13 in the static state corresponding to the current value of the open circuit voltage OCV of the battery 13 stored and stored in M25 is obtained, and the value of the pure resistance in the static state (true value) ) Shows how much the current value of the pure resistance of the battery 13 deviates, that is, indicates the degree of change in the state of the actual charge capacity of the battery 13 relative to the state of the charge capacity of the battery 13 in the static state.
A correction coefficient P unique to the battery 13 is obtained.

Specifically, for example, it is stored in the NVM 25,
The stored current open circuit voltage OCV of the battery 13
Is 12.5 (V), the value of the pure resistance of the battery 13 in the static state is 4.1 (Ω) from the open circuit voltage-pure resistance characteristic shown by the solid line in the graph of FIG. Is stored in the data area of the RAM 23b,
The stored current value of the pure resistance of the battery 13 is 5.
If it is 9 (Ω), the following calculation P = (5.9-4.1) /4.1≒0.439 is performed, and the value of the correction coefficient P of 0.439 is calculated.

When the starter switch or the large current switch is turned on, the integrated current value which is the time integrated value of the discharge current I of the battery 13 with respect to the motor generator 5 which functions as a cell motor, the power window motor or the headlight, is previously calculated. Is subtracted from the calculated initial electricity amount, the electricity amount of the discharging battery 13 is obtained by the current integration method, and the discharging battery 1 corresponding to the electricity amount is calculated.
3 is calculated and the open circuit voltage OCV is calculated.
The static state of charge SOC of the discharging battery 13 corresponding to the CV is calculated, and the previously calculated correction coefficient P is multiplied by the static state of charge SOC to obtain the actual state of charge SOC of the battery 13. Is calculated.

If the switch turned on is a switch other than the starter switch and the large current switch, the calculation of the pure resistance of the battery 13 and the correction coefficient P is omitted.
The same operation as when the turned-on switch is a starter switch or a large current switch is performed, the amount of electricity of the discharging battery 13 is calculated by the current integration method, and the amount of the discharging battery 13 corresponding to the amount of discharging is calculated. The open circuit voltage OCV is calculated, the static state of charge SOC of the discharging battery 13 corresponding to the open circuit voltage OCV is calculated, and the static state of charge SOC is multiplied by a correction coefficient P. The actual state of charge SOC of the battery 13 is calculated.

On the other hand, when it is recognized that the battery 13 is being charged by the electric power from the motor generator 5 or the like functioning as a generator, the battery 13
Whether the terminal voltage V of the reached steady state converge to set the charging voltage value V _T is monitored and when it has reached the stable state is confirmed, the increase in the charge-side polarization of the battery 13 is stopped, The internal resistance R + Rpol of the battery 13 at the start of the voltage stable region in which the charging-side polarization is saturated is obtained, assuming that the charging-side polarization is saturated.

The internal resistance R + Rpol and the charge
To the open circuit voltage OCV of the battery 13 before the start of power supply.
Of the battery 13 at the start of the new voltage stable region
Electromotive force E₀And the battery at the start of the
Charge current value I of battery 13_{CH G0}And the start of the voltage stable region
The value I of the charging current of the battery 13 measured thereafter_CHG1When
, The open circuit voltage OCV of the battery 13 being charged
_CHGIs the current battery 1 until the end of the constant voltage charging.
3 is repeatedly and periodically calculated as the open circuit voltage OCV.
It is.

[0235] In the vehicle battery charge capacity condition detecting apparatus 1 of the present embodiment, the terminal voltage V of the battery 13 being charged, has been described on the assumption that converge always set charging voltage value V _T, the actual Since the generator (motor generator 5 functioning as an alternator or a generator) serving as a power supply source for constant-voltage charging of the battery 13 is an AC generator, a high-frequency component is superimposed on the generated voltage waveform. As a cause, the constant voltage control of the charging voltage for the battery 13 may not work accurately, and the terminal voltage V of the battery 13 may slightly fluctuate.

Further, on the generator side for maintaining the charging voltage at a constant voltage, feedback control for reducing the charging current I _CHG due to the internal electromotive force E ₀ of the battery 13 does not work effectively, and overshoot or overshoot occurs. The terminal voltage V of the battery 13 may slightly fluctuate due to repetition of the undershoot.

Therefore, in step S10 in the flowchart of FIG. 17, when the charging current I and the terminal voltage V are collected from the current sensor 15 and the voltage sensor 17, the collected values are set to target settings previously set in the ROM 23c or the like. The target set charging voltage value V is compared with the charging voltage value V _{T.
When the} collected value is higher than _T, the internal electromotive force E ₀ ′ of the battery 13 after the start of the voltage stable region or the open circuit voltage OCV _CHG of the battery 13 being charged, which is equal to this, according to the error. Similarly, if the collected value is lower than the target set charging voltage value V _T , the internal electromotive force of the battery 13 after the start of the voltage stable region is determined according to the error. E ₀ ′, or an equivalent open circuit voltage O of the battery 13 during charging.
Correction for reducing CV _CHG may be performed to deal with subtle variations in the terminal voltage V of the battery 13.

As described above, the open circuit voltage OCV _CHG of the battery 13 being charged is changed to the current battery 13
Is calculated as the open circuit voltage OCV of the battery 13, the current amount of electricity of the battery 13 according to the open circuit voltage OCV is calculated, and the amount of electricity of the battery 13 is calculated by the current integration method during the discharge of the battery 13. Battery 13 used for
Is updated to the value after charging, and the static state of charge SOC of the discharging battery 13 corresponding to the calculated open circuit voltage OCV of the charging battery 13 is calculated. The static state of charge SOC is multiplied by the correction coefficient P, and the actual state of charge
C is calculated.

In the present embodiment, when measuring the current pure resistance R of the battery 13, actual data on the approximate curves represented by two approximate curve expressions M1 and M2 of the VI characteristic exist. Arbitrary points A and B are selected within the range, but these points are the points on the two approximated curve equations M1 and M2 that correspond to the maximum value of the battery discharge current measured to determine these equations. By selecting P and specifying both points using common data, it is possible to reduce the possibility of errors, and this will be specifically described below with reference to FIGS.

First, as shown in FIG. 28, a point P corresponding to the maximum value of the battery discharge current on the two approximate curve expressions M1 and M2 is selected. Then, a voltage drop ΔV1 from the intercept C1 to the vertical axis of the approximate curve of the equation M1 to the point P on the approximate curve is obtained. The value obtained by dividing ΔV1 by the current Ip at the point P is a combined resistance obtained by adding the value Rpol1 at that time of the polarization resistance component, which is another resistance component other than the pure resistance R, to the pure resistance R. That is, R + Rpol1 = ΔV1 / Ip.

Next, as shown in the figure, a voltage drop ΔV2 from the intercept C2 to the point P on the approximate curve of the approximate curve of the equation M2 is obtained. This ΔV2 is converted to the current I at the point P.
The value obtained by dividing by p is the value Rpol2 at that time of the polarization resistance component, which is a resistance component other than the pure resistance R, other than the pure resistance.
Is the combined resistance. That is, R + Rpol2 = ΔV2 / Ip.

The difference ΔR between the combined resistance value of the point P on the approximate curve of the equation M1 and the point P on the approximate curve of the equation M2 is ΔR = R + Rpol1- (R + Rpol2) = Rpol
1−Rpol 2, which is the difference between the polarization resistance components at a point P on a different approximate curve. This is apparent from the fact that the pure resistance R during one discharge does not change.

Note that on the approximate curve represented by the equation M1,
As shown in FIG. 29, there is a point P1 having a value (R + Rpol1 ′) equal to the combined resistance (R + Rpol2) at an arbitrary point P selected on the approximate curve of the equation M2. Further, as shown in FIG. 29, a value (R + pol) equal to the combined resistance (R + Rpol1) at an arbitrary point P selected on the approximate curve of the equation M1 is also displayed on the approximate curve represented by the equation M2.
There is a point P2 with 2 '). That is, R + Rp
The point P1 where ol1 '= R + Rpol2 is plotted on the approximate curve represented by the equation M1 as R + Rpol1 = R + Rpol2'.
Are present on the approximate curve represented by the equation M2.

In short, assuming that the current and voltage at point P1 are Ip1 and Vp1, respectively, and the current and voltage at point P2 are Ip2 and Vp2, respectively, the coordinates (Ip1, Vp1) of point P1 and the coordinates (Ip, Vp1) of point P ) Are equal to each other, and the coordinates (I
It can be seen that the values of the polarization resistance components of p, Vp) and the point P2 (Ip2, Vp2) are also equal to each other.

First, a method of calculating the current Ip1 and the voltage Vp1 of the point P1 having a value (R + Rpol1 ') equal to the value (R + Rpol1') of the combined resistance of the point P on the basis of the point P on the approximate curve of the equation M2. Will be described below.

Now, the voltage drop from the intercept C1 to the point P1 with respect to the vertical axis of the approximate curve represented by the equation M1 is represented by ΔVp1
When this is ^{ΔVp1 = C1- (a1Ip1 2 + b1p1} + C1) =
(R + Rpol2) Ip1. When this equation is rearranged,-(a1Ip1) + B1) = R + Rpol2, and the current Ip1 at the point P1 is Ip1 = − (b1 + R + Rpol2) / a1. Note that R + Rpol2 (= R + pol1 ′) =
Since ΔVp / Ip (= ΔVp1 / Ip1), Ip1 = − [b1 + (ΔVp / Ip)] / a1 = − [b1 + (ΔVp1 / Ip1)] / a1. Further, the voltage Vp1 at the point P1, as is clear from the above formula, since it is ^{Vp1 = a1Ip1 2 + b1Ip1 + C1} , coordinates (Ip1, Vp1) of the point P1 is determined from the known values.

Similarly, with the point P on the approximate curve of the equation M1 as a reference and the point P as a reference, the resistance value (R + R
pol1) and a point P having a value (R + Rpol2 ′) equal to
Second current Ip2 and the voltage Vp2 also, Ip2 = - [b2 + (ΔVp / Ip)] / a2 = - by [b2 + (ΔVp2 / Ip2)] ^{/ a2 Vp2 = a2Ip2 2 + b2Ip2} + C2 can be calculated from the known values. ΔVp2 is a voltage drop from the intercept C2 to the point P2 with respect to the vertical axis of the approximate curve represented by the equation M2.

As described above, the coordinates of the point P1 (Ip
1, Vp1) is determined, and as shown in FIG.
1 (Ip1, Vp1) and the coordinates of point P (Ip, Vp1)
The value R1 of the combined resistance is obtained by obtaining the slope of the straight line L1 connecting the line p) and the line p1. The value R1 of this combined resistance is
It is obtained by dividing the difference in voltage drop (Vp1-Vp) caused by the combined resistance composed of the pure resistance and the polarization resistance component Rpol2 by the difference in current flowing at each point (Ip1-Ip). That is, R1 = (Vp1-Vp) / (Ip1-Ip).

Similarly, the coordinates of point P2 (Ip2, Vp
When 2) is determined, as shown in FIG. 30, the slope of the straight line L2 connecting the coordinates (Ip2, Vp2) of the point P2 and the coordinates (Ip, Vp) of the point P is obtained, thereby obtaining the value R of the combined resistance.
2 is required. The value R2 of the combined resistance is obtained by dividing the difference (Vp-Vp2) of the voltage drop caused by the combined resistance composed of the pure resistance and the polarization resistance component Rpol1 by the difference (Ip-Ip2) of the current flowing at each point. Can be That is, R2 = (Vp-Vp2) / (Ip-Ip2).

However, the values R1 and R2 of the combined resistance obtained as described above are obtained by dividing the difference in voltage drop caused by the combined resistance composed of the pure resistance and the polarization resistance component by the difference in the current flowing at each point. It is obtained and does not match the pure resistance. In order to make the slope between the two points coincide with the pure resistance, the difference between the voltage drops excluding the voltage drop caused by the polarization resistance component may be divided by the current difference.

First, the case where the point P on the approximate curve of the equation M2 is used as a reference will now be described. Assuming that the value R1 of the combined resistance is R1 = R1 '+ Rpol2 = R1' + Rpol1 ', the point P1 is added to the resistance R1'. The voltage drop caused by the flow of the current corresponding to the difference between the current Ip1 of the point P and the current Ip of the point P is caused by the polarization resistance component Rpol1 ′ (or Rpo1 ′).
At l2), the voltage at the point P1 may be raised and corrected by the voltage drop caused by the flow of the current corresponding to the difference between the current Ip1 at the point P1 and the current Ip at the point P2, and the following equation is established. R1 '(Ip1-Ip) = [Vp1 + Rpol1' (I
p1-Ip)]-V2

By rearranging this equation, R1 '(Ip1-Ip) = (Vp1-Vp) + Rpol
1 '(Ip1-Ip). Here, Rpol1 ′ = ΔVp1 / Ip1-R
1 ′, R1 ′ (Ip1−Ip) = (Vp1−Vp) + (ΔVp
1 / Ip1-R1 ') (Ip1-Ip) 2R1' (Ip1-Ip) = (Vp1-Vp) +. DELTA.Vp
1 / Ip1 (Ip1-Ip), and as a result, R1 '= [(Vp1-Vp) + (ΔVp1 / Ip1)
(Ip1-Ip)] / 2 (Ip1-Ip) is obtained. Note that (ΔVp1 / Ip1) is (ΔV2
/ Ip).

Next, in the case where R2 = R2 '+ Rpol1 = R2' + Rpol2 'in the same manner on the basis of the point P on the approximate curve of the equation M1, the current Ip of the point P and the point The voltage drop caused by the flow of the current corresponding to the difference between the currents Ip2 of P2 is caused by the polarization resistance component Rpol2 ′ (or Rp2 ′).
ol1), the voltage at the point P2 may be lowered and corrected by the voltage drop caused by the flow of the current corresponding to the difference between the current Ip at the point P and the current Ip2 at the point P2, and the following equation is established. R2 '(Ip-Ip2) = Vp- [Vp2-Rpol
2 '(Ip-Ip2)]

By rearranging this equation, R2 '(Ip-Ip2) = (Vp-Vp2) + Rpol
2 ′ (Ip−Ip2). Here, Rpol2 ′ = ΔVp2 / Ip2-R
2 ′, R2 ′ (Ip−Ip2) = (Vp−Vp2) + (ΔVp
2 / Ip2-Rp2) (Ip-Ip2) 2R2 '(Ip-Ip2) = (Vp-Vp2) +. DELTA.Vp
2 / Ip2 (Ip−Ip2), and as a result, R2 ′ = [(Vp−Vp2) + (ΔVp2 / Ip2)
(Ip-Ip2)] / 2 (Ip-Ip2). (ΔVp2 / Ip2) is (ΔVp2 / Ip2)
/ Ip).

The two values R1 'obtained as described above
And R2 ′ are based on two points A and B, and have different polarization resistance components (Rpol1 ′ = Rpol2) and (Rpol1).
1 = Rpol2 ′) and the voltage drop ΔVp1 (ΔVp) from the different intercept C1 and the voltage drop ΔVp2 (ΔVp) from the intercept C2.
It cannot be a true pure resistance R. Therefore, the true pure resistance R is obtained by taking the average of the two, R = (R1 '+ R2') / 2.

In the battery pure resistance measuring method described with reference to FIGS. 28 to 30, a point P is set at a point on the two approximated curve expressions M1 and M2 corresponding to the maximum value of the battery discharge current. Since identification is performed using common data, errors can be reduced.

When the discharge current Ip corresponding to the point P on the curve represented by the second approximate curve equation M2 flows, the second
A second combined resistance R consisting of a battery pure resistance and a second polarization resistance component Rpol2 that causes a voltage drop ΔV2 of
When a discharge current Ip corresponding to a point P on the curve represented by the first approximate curve M1 flows through the first assumed point P1 having the same resistance value as the second approximate curve P1 on the first approximate curve equation M1. A second assumed point P2 having the same resistance value as the first combined resistance R1 composed of the pure resistance of the battery and the first polarization resistance component Rpol1, which causes the first voltage drop ΔV1, is calculated by a second approximate curve equation. Each is assumed on M2.

When the two assumed points P1 and P2 can be assumed, the first slope R1 of the straight line L1 connecting the point P and the first assumed point P1 is determined by the discharge current Ip and the discharge at the first assumed point P1. And the current Ip1, the difference Rpol2 (Ip2) of the voltage drop due to the second polarization resistance component Rpol2.
1−Ip), the first correction slope R excluding the voltage drop due to the second polarization resistance component Rpol2.
1 ′, the point P and the second assumed point P
And the second slope R2 of the straight line L2 connecting the discharge current Ip
And the discharge current Ip2 at the second assumed point P2, the first polarization resistance component Rpol1 is corrected by an amount corresponding to the difference Rpol1 (Ip−Ip2) of the voltage drop due to the first polarization resistance component Rpol1. To obtain a second correction slope R2 'excluding the voltage drop due to.

The first correction inclination R thus obtained
The average slope is obtained by adding and averaging 1 'and the second correction slope R2', and the obtained average slope is measured as the pure resistance R of the battery.

The specific procedure for measuring the pure resistance in this way is that two points are determined at a common point P corresponding to the maximum value of the battery discharge current on the two approximate curve expressions M1 and M2. Except for this, since the procedure of measuring the pure resistance described above with reference to FIGS. 13 to 15 is the same as that of FIG. 24 and can be executed by substantially the same processing as the processing shown in the flowchart of FIG. I do.

As described above, according to the battery state-of-charge measuring apparatus 1 of the present embodiment, the battery 13 eliminates at least the charging-side polarization that has occurred immediately before discharging when the starter switch or the large current switch is turned on. The current pure resistance corresponding to the actual charge capacity of the battery 13 based on the periodically measured terminal voltage V and the discharge current I when a constant load discharge with a current value sufficient to perform The current open circuit voltage OCV of the battery 13 is obtained, and the value of the pure resistance in the current static state of the battery 13 corresponding to the open circuit voltage OCV is determined by the predetermined open circuit voltage−static Calculated from the resistance characteristics, the current pure resistance of the battery 13 in the static state and the current battery 1
The value obtained by dividing the difference between the actual pure resistance of the battery 3 and the actual pure resistance of the battery 13 in the static state of the battery 13 is the battery 1
3 as a correction coefficient P corresponding to the current state,
The state of charge S of the battery 13 in the static state obtained based on the charge / discharge current I of the battery 13 and the terminal voltage V
When the OC is corrected and the actual state of charge SOC of the battery 13 is obtained, the correction coefficient P is used.

For this reason, when deterioration of the battery 13 or a change in temperature occurs, the correction coefficient is not set uniformly according to the representative characteristics of the battery 13 having the same specification, but is changed individually. The state of charge SOC of the battery 13 in the static state is calculated using the correction coefficient P corresponding to the current state of deterioration and temperature of the battery 13, which is obtained based on the current pure resistance reflecting the subtle characteristic difference of the battery 13. Is corrected so that even if the specifications are the same and there is a characteristic difference between individuals, the actual state of charge of the battery 13 SO
C can be determined with high accuracy.

In this embodiment, the battery 13
Although the case where the state of charge SOC of the battery 13 is detected has been described as the state related to the charge capacity of the battery 13, a chargeable capacity value, a dischargeable capacity value, and the like may be detected as the state related to the charge capacity of the battery 13.

Further, in the present embodiment, the case where the method and apparatus for calculating the correction coefficient for detecting the state of charge of the battery of the present invention has been described for a battery state-of-charge measuring device mounted on a hybrid vehicle. Is
When calculating a correction coefficient used to detect the state of charge of a battery mounted on various vehicles, such as a general 14V vehicle, a multi-powered vehicle such as 14V and 42V, and an electric vehicle,
It goes without saying that it is widely applicable.

[0265]

As described above, according to the method for calculating the correction coefficient for detecting the state of charge of a battery according to the first aspect of the present invention, during charging or discharging of a battery for supplying power to a vehicle load. An open circuit voltage corresponding to a terminal voltage of the battery in an equilibrium state is calculated based on a charging current and a discharging current of the battery and a terminal voltage which are periodically measured during the charging and discharging during the charging and discharging of the battery. A value indicating a state relating to the charge capacity of the battery in a static state is obtained based on the open circuit voltage thus obtained, and the value in the static state is determined according to a current deterioration degree or a current temperature of the battery. By correcting with a correction coefficient corresponding to the difference between the current state and the static state of the battery, when detecting the value indicating the state of the battery regarding the actual charge capacity, A method of calculating the correction coefficient corresponding to the current state of battery, wherein an open circuit voltage-pure resistance characteristic of the battery when new is determined in advance, and the battery is generated in the battery at least immediately before discharging. The current charging capacity of the battery is determined based on the terminal voltage and the discharge current of the battery periodically measured when a constant load discharge is performed with a current value sufficient to eliminate the charging-side polarization that has occurred. Determining the current pure resistance of the battery corresponding to the state of the battery, and determining the current open circuit voltage of the battery based on the terminal voltage of the battery measured before the start of the constant load discharge. The value of the pure resistance when the battery is new, corresponding to the current open circuit voltage of
Determined from the pure resistance characteristic, the value of the determined pure resistance of the battery at the time of new product corresponding to the current open circuit voltage of the battery, and the current value of the battery determined at the time of the constant load discharge of the battery. A value obtained by dividing a difference value between the value of the pure resistance and the value of the determined pure resistance of the battery when the battery is new is calculated as the correction coefficient corresponding to the current state of the battery.

For this reason, at least the current net current obtained based on the terminal voltage and the discharge current when the battery performs a constant load discharge at a current value sufficient to eliminate at least the charge-side polarization generated immediately before the discharge. The resistance corresponds to the current open circuit voltage of the battery determined from an open circuit voltage-pure resistance characteristic indicating a correlation between the open circuit voltage of the battery and a predetermined pure resistance in a static state of the battery. By the pure resistance of the battery in the static state, a value specific to the battery is obtained, which indicates the degree of change of the state related to the actual charge capacity of the battery with respect to the state related to the charge capacity of the battery in the static state. Based on the terminal voltage of the battery measured before the start of constant load discharge with a current value sufficient to eliminate the charging side polarization that has occurred. By multiplying the current open-circuit voltage of the battery by the calculated value, it is not a value indicating the state related to the charge capacity of the battery in a static state where the amount of change due to deterioration or temperature of the battery is not reflected. A correction coefficient capable of detecting a value indicating a state relating to the charge capacity can be accurately calculated even for a battery having the same specification and a large allowable range of a characteristic difference between individuals.

According to the second aspect of the present invention, there is provided a method of calculating a correction coefficient for detecting a state of charge of a battery according to the first aspect of the present invention. The terminal voltage and discharge of the battery measured periodically when the battery performs constant load discharge at a current value sufficient to at least eliminate the charging-side polarization that has occurred in the battery immediately before discharge. A first approximation curve expression of the voltage-current characteristic showing a correlation between the terminal voltage of the battery and the discharge current during the increase of the discharge current, and the terminal voltage and the discharge of the battery during the decrease of the discharge current. The voltage-indicating a correlation with the current-
A second approximation curve equation of the current characteristic is obtained, and a first point on the voltage-current characteristic curve represented by the first approximation curve equation is set to the voltage-voltage represented by the second approximation curve equation. A second point is defined on the current characteristic curve, and a second voltage drop is caused when a second discharge current corresponding to the second point flows, a pure resistance and a second polarization resistance of the battery. A first assumed point having the same resistance value as the second combined resistance composed of the components is assumed on the voltage-current characteristic curve represented by the first approximate curve equation, and A second assumption having a resistance value equal to a first combined resistance consisting of a pure resistance of the battery and a first polarization resistance component, which causes a first voltage drop when a corresponding first discharge current flows. The point is represented by a voltage-current characteristic curve represented by the second approximate curve equation. Assuming above, a first slope of a straight line connecting the second point and the first assumed point is caused by the second discharge current and the discharge current at the first assumed point, respectively. The first correction slope excluding the voltage drop due to the second polarization resistance component is obtained by correcting the amount corresponding to the difference between the voltage drops due to the second polarization resistance component, and the first point and the first point are corrected. The difference between the voltage drop due to the first polarization resistance component, which is caused by the first discharge current and the discharge current at the second assumed point, respectively, with a second slope of a straight line connecting to the second assumed point. Correct the amount corresponding to
A second correction slope excluding the voltage drop due to the first polarization resistance component is obtained, and the obtained first and second slopes are averaged to obtain an average slope. It was determined as the current pure resistance of the battery.

For this reason, in the battery charge capacity state detection correction coefficient calculating method according to the first aspect of the present invention, the battery terminal voltage and the discharge current periodically measured during constant current discharge at a predetermined large current. Since the pure resistance of the battery can be determined simply by processing the data obtained from the battery, the terminal voltage and the discharge current of the battery when the power is supplied to the load in the normal use condition of the vehicle are measured. By simply processing the data obtained as a result, the pure resistance of the battery can be measured when the battery is used in a normal state, that is, even when the vehicle is in use.

According to the third aspect of the present invention, there is provided a method for calculating a correction coefficient for detecting a charged capacity state of a battery according to the present invention.
3. The method according to claim 2, wherein the first point and the second point are defined by the first approximate curve expression and the second approximate curve. 4. In order to obtain the equation, the point was set to an arbitrary point within a range where the measured terminal voltage and discharge current of the battery existed.

For this reason, in the method of calculating the correction coefficient for detecting the state of charge of a battery according to the second aspect of the present invention, at least one of the slopes between two points for measuring the current pure resistance of the battery is provided. Is based on the actual data, and it is possible to eliminate the use of a point that deviates greatly from the actual, so that the accuracy of measuring the current pure resistance of the battery can be kept stable.

According to the fourth aspect of the present invention, there is provided a method for calculating a correction coefficient for detecting a state of charge of a battery according to the present invention. In the method, the first point and the second point are converted to the first approximate curve equation and the second approximate curve equation on the first approximate curve equation and the second approximate curve equation. In order to obtain it, a point corresponding to the maximum value of the measured discharge current of the battery was set.

Therefore, in the battery charge capacity state detection correction coefficient calculating method according to the present invention, two points are calculated by calculating the maximum of the battery discharge current measured to obtain each approximate curve equation. As a point corresponding to the current value, at least one for obtaining the slope is based on actual data, it is possible to eliminate the use of a point that deviates greatly from the actual, and both points are common, Since errors can be reduced as compared with those using different data, the accuracy of measuring the current pure resistance of the battery can be kept stable.

Further, according to the method of calculating the correction coefficient for detecting the state of charge of a battery according to the present invention,
5. The method according to claim 2, wherein the first approximate curve equation and the second approximate curve equation are measured periodically. The terminal voltage and the discharge current of the battery are collected, stored, and stored for the latest predetermined time.

Therefore, in the method for calculating the correction coefficient for detecting the state of charge of the battery according to the second, third or fourth aspect of the present invention, it is necessary to obtain two approximate curve equations using the stored actual data. After confirming that the discharge current has flowed, the approximate curve equation can be obtained using the stored actual data, so that unnecessary processing can be omitted and the battery can be stored without performing real-time high-speed processing. The current pure resistance can be measured.

According to the charging capacity state detection correction coefficient calculating method of the present invention described in claim 6,
In the method for calculating the correction coefficient for detecting the charged capacity state of a battery according to the present invention described in 2, 3, 4, or 5, a predetermined time after a predetermined time has elapsed after the charging or discharging of the battery is completed. The open circuit voltage of the battery is measured a plurality of times in between, and a predetermined exponential approximation in which the exponent is negative is determined based on the difference between the measured open circuit voltage and the assumed open circuit voltage. Power of the power approximation formula
0.5, or, until it becomes approximately -0.5, repeatedly determines the power approximation formula while updating the assumed open circuit voltage, and the exponent becomes -0.5, Or
The assumed open circuit voltage when the voltage becomes approximately -0.5 is obtained as the current open circuit voltage of the battery.

Therefore, in the method for calculating the correction coefficient for detecting the state of charge of a battery according to the present invention, a relatively short time after the completion of charging or discharging of the battery. The asymptote of a power approximation that does not change under the influence of temperature can be obtained by measuring the open-circuit voltage of the battery measured in the battery, and this can be obtained as the current open-circuit voltage of the battery. The current open circuit voltage can be determined relatively accurately within a relatively short time after the end of charging / discharging and without the need for temperature correction.

Further, according to the method of calculating the correction coefficient for detecting the state of charge of a battery according to the present invention,
7. The method according to claim 6, wherein when the measured open circuit voltage is after the end of the charging of the battery, the time is represented by t and the unknown coefficient is calculated. Is α, unknown negative power is D
Then, the power approximation equation is represented by α · t ^D.

Therefore, in the battery charge capacity state detection correction coefficient calculating method according to the present invention, the open-circuit voltage of the battery measured within a relatively short time after the battery charge is completed. As a result, an asymptote of a power approximation that does not change under the influence of temperature can be obtained, and this can be obtained as the current open circuit voltage of the battery. Can be determined within a relatively short period of time, and without the need for temperature correction.

[0279] According to the method of calculating the correction coefficient for detecting the state of charge of the battery according to the present invention as set forth in claim 8, the method of calculating the correction coefficient for detecting the state of charge of the battery according to claim 6 of the present invention. When the measured open circuit voltage is after the end of discharging of the battery,
The value for determining the power approximation formula is an absolute value of a value obtained by subtracting the assumed open circuit voltage from the measured open circuit voltage, time is t, unknown coefficient is α, unknown negative Assuming that the exponent is D, the power approximate expression is represented by α · t ^D.

Therefore, in the battery charge capacity state detection correction coefficient calculating method according to the present invention, the measurement of the open circuit voltage of the battery measured within a relatively short time after the discharge of the battery is completed. As a result, the asymptote of a power approximation that does not change under the influence of temperature can be obtained and this can be obtained as the current open circuit voltage of the battery. Can be determined within a relatively short period of time, and without the need for temperature correction.

Further, according to the method of calculating the correction coefficient for detecting the charged state of the battery according to the ninth aspect,
The method of calculating a correction coefficient for detecting a state of charge of a battery according to claim 7 or 8, wherein the open-circuit voltage measured during the predetermined time is an arbitrary number of 2 or more,
An arbitrary number of open-circuit voltages obtained by the measurement and the time from the end of charging / discharging are subjected to regression calculation processing, and the exponent D
Was decided.

Therefore, in the battery charge capacity state detecting correction coefficient calculating method according to the present invention, a large number of measured battery capacities within a relatively short time after charging / discharging of the battery is completed. By measuring the open-circuit voltage, the asymptote of the power approximation that does not change under the influence of temperature can be accurately obtained, and this can be obtained as the current open-circuit voltage of the battery. The voltage can be determined within a relatively short time from the end of charging and discharging, and without the need for temperature correction.

Further, according to the method for calculating the correction coefficient for detecting the state of charge of a battery according to the present invention,
The method according to claim 1, 2, 3, 4, or 5, wherein the elapsed time after the charging or discharging of the battery is completed is:
Measuring the open voltage of the battery a plurality of times during a period from a predetermined first time to a predetermined second time;
After the charging or discharging of the battery is completed from the measured open circuit voltage, the second time after the first time has elapsed.
For the time until the elapsed time, showing the correlation between the open voltage and the elapsed time from the end of the charge or discharge,
The predetermined straight line approximation formula is determined, and the determined straight line when the predetermined third time longer than the second time is substituted as the elapsed time from the end of charging or discharging of the battery. The solution of the approximate expression is determined as the current open circuit voltage of the battery.

Therefore, according to the method of calculating the correction coefficient for detecting the state of charge of the battery according to the present invention, the open voltage of the battery is determined after the charging or discharging of the battery is completed. The linear approximation formula is obtained by measuring the open circuit voltage of the battery within a relatively short time when the value of the battery changes only to the extent that the approximation can be approximated by a linear approximation. Since the current open circuit voltage can be determined, the current open circuit voltage of the battery during vehicle use can be compared within a relatively short time from the end of charging and discharging, and without the need for temperature correction. It can be obtained accurately.・ Claim 22

Further, according to the method of calculating the correction coefficient for detecting the state of charge of the battery according to the present invention described in claim 11, the method of calculating the correction coefficient for detecting the state of charge of the battery according to claim 10 of the present invention. If the elapsed time from the end of charging or discharging of the battery is t, the unknown coefficient is c, and the unknown complement is E, the linear approximation formula is c · t
+ E.

For this reason, in the method of calculating the correction coefficient for detecting the state of charge of the battery according to the present invention, the open-circuit voltage of the battery can be changed within a relatively short period of time when the open-circuit voltage changes only to an extent that can be approximated by a straight line. Substituting the third time as the value of t into the linear approximation expression c · t + E obtained by measuring the open-circuit voltage of the battery, the elapsed time after the end of charging or discharging is determined by a predetermined third time By calculating the open circuit voltage of the battery at the time when the battery becomes in use, it is necessary to correct the temperature of the current open circuit voltage of the battery during use of the vehicle within a relatively short time from the end of charging and discharging. Can be determined relatively accurately and easily without doing so.

Further, according to the correction coefficient calculating apparatus for detecting the state of charge of a battery according to the twelfth aspect,
An open circuit corresponding to a terminal voltage in an equilibrium state of the battery, based on a charging current and a discharging current of the battery and a terminal voltage which are periodically measured during charging and discharging of the battery that supplies power to a vehicle load. Calculating a voltage, based on the open circuit voltage calculated during charging or discharging of the battery, a value indicating a state related to the charge capacity of the battery in a static state without a state change due to deterioration and temperature fluctuation, By correcting the value in the static state by a correction coefficient corresponding to a difference between the current state and the static state of the battery corresponding to the current deterioration degree and the current temperature of the battery, An apparatus for calculating a correction coefficient corresponding to a current state of the battery when detecting a value indicating a state related to an actual charge capacity of the battery. A characteristic storage means in which an open circuit voltage-pure resistance characteristic of the battery is stored in advance; and a constant value determined by the battery at least sufficient to eliminate the charging-side polarization generated in the battery immediately before discharging. A pure resistance measurement for obtaining a current pure resistance of the battery corresponding to a state related to a current charge capacity of the battery based on a terminal voltage and a discharge current of the battery periodically measured when a load discharge is performed. Means, an open circuit voltage measuring means for obtaining a current open circuit voltage of the battery based on a terminal voltage of the battery measured before the start of the constant load discharge, and the open circuit voltage measuring means obtained by the open circuit voltage measuring means. The value of the pure resistance in the static state of the battery corresponding to the current open circuit voltage of the battery is obtained by subtracting the open circuit voltage−the pure resistance stored in the characteristic storage means. A static pure resistance value determining means for determining from the characteristic, and the battery corresponding to a current open circuit voltage of the battery determined by the open circuit voltage measuring means, which is determined by the static pure resistance value determining means. The difference between the value of the pure resistance in the static state of the battery and the value of the current pure resistance of the battery obtained by the pure resistance measuring means at the time of the constant load discharge of the battery is the static pure resistance value. Calculating means for calculating a value obtained by dividing by a value of a pure resistance in a static state of the battery corresponding to the current open circuit voltage of the battery determined by the open circuit voltage measuring means, which is determined by the determining means. And the value calculated by the calculation means is calculated as the correction coefficient corresponding to the current state of the battery.

For this reason, the pure resistance measuring means can determine the pure resistance based on the terminal voltage and the discharge current when the battery has performed a constant load discharge at a current value sufficient to at least eliminate the charge-side polarization that occurred immediately before the discharge. A static pure resistance value division is obtained from the obtained pure resistance and an open circuit voltage-pure resistance characteristic indicating a correlation between the pure resistance in the static state of the battery and the open circuit voltage of the battery stored in the characteristic storage means. The degree of change of the state related to the actual charge capacity of the battery with respect to the state related to the charge capacity of the battery in the static state, by the pure resistance of the battery in the static state corresponding to the current open circuit voltage of the battery determined by the output means A value specific to the battery is obtained by the calculating means, and a constant load discharge at a current value sufficient to eliminate at least the charging-side polarization that occurred immediately before the discharge. It was measured at the start point in time earlier,
By multiplying the current open circuit voltage of the battery obtained based on the terminal voltage of the battery, the state related to the charge capacity of the battery in a static state in which the change due to the deterioration or temperature of the battery is not reflected is indicated. Correctly calculate not the value but the correction coefficient that can detect the value related to the actual charge capacity of the battery, even for batteries with the same specification but with a large permissible range of characteristic differences between individuals. Can be.

Further, according to the battery charge capacity state detecting correction coefficient calculating device of the present invention described in claim 13, the battery charge capacity state detecting correction coefficient calculating device of the present invention according to claim 12 is provided. The pure resistance measuring means periodically measures at the time of constant load discharge at a current value sufficient to eliminate the charging side polarization of the battery at least immediately before discharging. From the terminal voltage and the discharge current, a first approximation curve expression of the voltage-current characteristic showing a correlation between the terminal voltage and the discharge current of the battery during the increase of the discharge current, and the battery of the battery during the decrease of the discharge current An approximate curve expression calculating means for obtaining a second approximate curve expression of the voltage-current characteristic indicating a correlation between the terminal voltage and the discharge current; and an electric line represented by the second approximate curve expression. A first, consisting of a pure resistance of the battery and a first polarization resistance component, which causes a second voltage drop when a second discharge current corresponding to a second point defined on the current characteristic curve flows; A first assumed point having the same resistance value as the combined resistance is assumed on a voltage-current characteristic curve represented by the first approximate curve equation, and a voltage represented by the first approximate curve equation is assumed. A pure resistance of the battery and a second resistance which cause a first voltage drop when a first discharge current corresponding to a first point defined on the current characteristic curve flows;
Assuming a second assumed point having the same resistance value as the second combined resistance composed of the polarization resistance component on the voltage-current characteristic curve represented by the second approximate curve equation, A voltage generated by the second polarization resistance component, which causes a first slope of a straight line connecting a point and the first assumed point to be generated by the second discharge current and the discharge current at the second assumed point, respectively. A first correction slope excluding a voltage drop due to the second polarization resistance component is obtained by correcting an amount corresponding to a difference between the drops, and a straight line connecting the first point and the second assumed point. Is corrected by an amount corresponding to the difference in voltage drop due to the first polarization resistance component, which is caused by the first discharge current and the discharge current at the second assumed point, respectively, The second correction slope excluding the voltage drop due to the first polarization resistance component And a second calculating means for calculating an average slope by adding and averaging the obtained first correction slope and the second correction slope, and calculating the average slope calculated by the second calculating means. The configuration was determined as the current pure resistance of the battery.

For this reason, in the battery charge capacity state correction coefficient calculating apparatus according to the present invention, the terminal voltage and the discharge current of the battery periodically measured at the time of constant current discharge with a predetermined large current. Since the pure resistance of the battery can be determined simply by processing the data obtained from the battery, the terminal voltage and the discharge current of the battery when the power is supplied to the load in the normal use condition of the vehicle are measured. By simply processing the data obtained as a result, the pure resistance of the battery can be measured when the battery is used in a normal state, that is, even when the vehicle is in use.

Further, according to the battery charge capacity state detecting correction coefficient calculating apparatus of the present invention,
14. The correction coefficient calculating apparatus according to claim 13, wherein the first point and the second point are defined by the first approximate curve expression and the second approximate curve. In order to obtain the formula, the configuration was set to an arbitrary point within the range where the measured terminal voltage and discharge current of the battery existed.

For this reason, in the battery charge capacity state correction coefficient calculating apparatus according to the present invention, at least one of the slopes between two points for measuring the current pure resistance of the battery is calculated. Is based on the actual data, and it is possible to eliminate the use of a point that deviates greatly from the actual, so that the accuracy of measuring the current pure resistance of the battery can be kept stable.

Furthermore, according to the battery charge capacity state detection correction coefficient calculating device of the present invention described in claim 15, the battery charge capacity state detecting correction coefficient calculation device of the present invention described in claim 13 or 14 is provided. In the apparatus, the first point and the second point are defined as the first approximate curve equation and the second approximate curve equation on the first approximate curve equation and the second approximate curve equation. In order to obtain the value, a point corresponding to the maximum value of the measured discharge current of the battery was adopted.

Therefore, in the battery charge capacity state detection correction coefficient calculating apparatus according to the present invention, two points are calculated by calculating the maximum of the battery discharge current measured to obtain each approximate curve equation. As a point corresponding to the current value, at least one for obtaining the slope is based on actual data, it is possible to eliminate the use of a point that deviates greatly from the actual, and both points are common, Since errors can be reduced as compared with those using different data, the accuracy of measuring the current pure resistance of the battery can be kept stable.

Further, according to the battery charge capacity state detecting correction coefficient calculating apparatus of the present invention,
16. The correction coefficient calculating device for detecting the state of charge of a battery according to claim 13, 14 or 15, wherein the approximate curve equation calculating means calculates the first approximate curve equation and the second approximate curve equation. In order to obtain the terminal voltage and the discharge current of the battery periodically measured at the time of constant load discharge of the battery, a storage means is provided for collecting, storing and storing the latest predetermined time.

For this reason, in the correction coefficient calculating apparatus for detecting the state of charge of a battery according to the present invention, two approximate curve equations are obtained by using the actual data stored in the storage means. After confirming that the necessary discharge current has flowed, the approximate curve equation can be obtained using the stored actual data, so that unnecessary processing can be omitted and real-time high-speed processing can be performed. , The current pure resistance of the battery can be measured.

Further, according to the battery charge capacity state detecting correction coefficient calculating device of the present invention described in claim 17, the battery charge capacity of the present invention described in claim 12, 13, 14, 15, or 16 is provided. In the state detection correction coefficient calculating device, the open circuit voltage measuring means measures an open voltage of the battery for a predetermined time after a predetermined time has elapsed after the charging or discharging of the battery is completed. Open-circuit voltage measuring means, a plurality of open-circuit voltages obtained by measuring the open-circuit voltage means a plurality of times, and a difference value between the assumed open-circuit voltage and a predetermined exponential approximation in which the exponent is negative. Determining the power approximation equation until the exponent of the power approximation equation determined by the approximation equation determination means is -0.5 or approximately -0.5. Determination of the approximate expression And a calculation control means for updating the assumed open circuit voltage and repeatedly executing the same, and the expected open circuit when the exponent becomes -0.5 or substantially -0.5. The circuit voltage is determined as the current open circuit voltage of the battery.

For this reason, claims 12, 13, 14, 15
In the correction coefficient calculating apparatus for detecting a charged capacity state of a battery according to the present invention described in 16 or 17, the influence of temperature is measured by measuring the open-circuit voltage of the battery measured within a relatively short time after the charging or discharging of the battery is completed. As a result, an asymptote of a power approximation that does not change can be obtained and this can be obtained as the current open circuit voltage of the battery, so that the current open circuit voltage of the vehicle battery can be relatively short from the end of charging and discharging. It can be determined relatively accurately in time and without the need for temperature correction.

Further, according to the battery charging capacity state detecting correction coefficient calculating apparatus of the present invention,
18. The battery charge capacity state correction coefficient calculating apparatus according to claim 17, wherein when the measured open-circuit voltage is after the end of charging of the battery, time is represented by t, and an unknown coefficient is calculated. Is α, unknown negative power is D
, The power approximation equation is represented by α · t ^D.

For this reason, in the battery charge capacity state detection correction coefficient calculating apparatus according to the present invention, the battery open-circuit voltage measured within a relatively short time after the battery charge is completed. As a result, an asymptote of a power approximation that does not change under the influence of temperature can be obtained, and this can be obtained as the current open circuit voltage of the battery. Can be determined within a relatively short period of time, and without the need for temperature correction.

Furthermore, according to the battery charging capacity state detecting correction coefficient calculating device of the present invention described in claim 19, the battery charging capacity state detecting correction coefficient calculating device of the present invention described in claim 17 is provided. The value for determining the power approximation formula is obtained by subtracting the assumed open circuit voltage from the measured open voltage when the measured open circuit voltage is obtained after the discharge of the battery is completed. When the time is t, the unknown coefficient is α, and the unknown negative exponent is D, the power approximation equation is expressed as α · t ^D.

Therefore, in the battery charge capacity state detecting correction coefficient calculating device according to the present invention, the battery open-circuit voltage measured within a relatively short time after the battery discharge is completed. As a result, the asymptote of a power approximation that does not change under the influence of temperature can be obtained and this can be obtained as the current open circuit voltage of the battery. Can be determined within a relatively short period of time, and without the need for temperature correction.

Further, according to the correction coefficient calculating apparatus for detecting the state of charge of a battery according to the present invention,
20. The apparatus according to claim 18 or 19, wherein the approximate expression determining means measures at least two arbitrary values measured during the predetermined time by the open-circuit voltage measuring means. The number open voltage and the time from the end of charging / discharging are regression-calculated to determine the exponent D of the power approximation.

Therefore, in the battery charge capacity state detecting correction coefficient calculating apparatus according to the present invention, a large number of measured battery capacities are measured within a relatively short time after charging / discharging of the battery is completed. By measuring the open-circuit voltage, the asymptote of the power approximation that does not change under the influence of temperature can be accurately obtained, and this can be obtained as the current open-circuit voltage of the battery. The voltage can be determined within a relatively short time from the end of charging and discharging, and without the need for temperature correction.

Further, according to the battery charge capacity state detecting correction coefficient calculating device of the present invention described in claim 21, the battery charge capacity of the present invention described in claim 12, 13, 14, 15, or 16 is provided. In the state detection correction coefficient calculating device, the open circuit voltage measuring means may be configured to determine whether an elapsed time after the charging or discharging of the battery is completed reaches a predetermined second time from a predetermined first time. Between the second open-circuit voltage measuring means for measuring the open-circuit voltage of the battery, and a plurality of open-circuit voltages obtained by measuring a plurality of times by the second open-circuit voltage measuring means, after completion of the charging or discharging, A predetermined linear approximation formula showing a correlation between the open-circuit voltage and the elapsed time from the end of the charging or discharging, for a period from when the first time has elapsed to when the second time has elapsed. Decide A second approximation formula determining unit, and a second approximation formula determining unit that substitutes a predetermined third time longer than the second time as an elapsed time from the end of the charging or discharging. Calculating means for calculating a solution of the determined linear approximation formula, wherein the solution calculated by the calculating means is obtained as a current open circuit voltage of the battery.

Therefore, claims 12, 13, 14, 15
Alternatively, in the correction coefficient calculating device for detecting a charged capacity state of a battery according to the present invention as described in 16 above, after charging or discharging of the battery is completed, a relatively short time in which the open-circuit voltage of the battery changes only to an extent that it can be approximated by a substantially straight line By measuring the open circuit voltage of the battery within the
Since the current open circuit voltage of the battery can be obtained from this linear approximation as a value that does not change under the influence of temperature, the current open circuit voltage of the battery during use of the vehicle can be calculated relatively from the end of charging and discharging. It can be determined relatively accurately within a short time and without the need for temperature correction.

According to the correction coefficient calculating apparatus for detecting the state of charge of a battery according to the present invention,
The correction coefficient calculation device for detecting a charged capacity state of a battery according to the present invention according to claim 21, wherein the elapsed time from the end of charging or discharging of the battery is t, the unknown coefficient is c,
Assuming that the unknown complement is E, the linear approximation formula is ct + E
The configuration represented by

Therefore, in the battery charge capacity state detecting correction coefficient calculating apparatus according to the present invention, the open-circuit voltage of the battery changes within a relatively short period of time when the open-circuit voltage changes only to an extent that it can be approximated to a linear approximation. Substituting the third time as the value of t into the linear approximation expression c · t + E obtained by measuring the open-circuit voltage of the battery, the elapsed time after the end of charging or discharging is determined by a predetermined third time By calculating the open circuit voltage of the battery at the time when the battery becomes in use, it is necessary to correct the temperature of the current open circuit voltage of the battery during use of the vehicle within a relatively short time from the end of charging and discharging. Can be determined relatively accurately and easily without doing so.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram of a correction coefficient calculation device for detecting a charged capacity state of a battery according to the present invention.

FIG. 2 is a basic configuration diagram of a correction coefficient calculating device for detecting a charged capacity state of a battery according to the present invention.

FIG. 3 is a graph showing a change in an open circuit voltage of a battery after charging is completed.

FIG. 4 is a graph for explaining a first concept of battery open circuit voltage measurement that can be employed in the present invention.

FIG. 5 is another graph for explaining the first concept of the open circuit voltage measurement of the battery that can be employed in the present invention.

FIG. 6 is a graph specifically illustrating the validity of a first concept of battery open circuit voltage measurement that can be employed in the present invention.

FIG. 7 is a graph showing a change in the open-circuit voltage of the battery after the end of charging, which varies depending on the temperature and is used to explain a second concept of the open-circuit voltage measurement of the battery that can be employed in the present invention.

FIG. 8 is another graph illustrating a second concept of battery open circuit voltage measurement that can be employed in the present invention.

FIG. 9 is a graph showing an example of a voltage-current characteristic of a battery expressed by a first-order approximation formula.

FIG. 10 is a graph showing an example of a voltage-current characteristic of a battery expressed by a second-order approximation formula.

FIG. 11 is a graph showing an example of a change in polarization with respect to a current.

FIG. 12 is a graph showing an example of an approximate characteristic curve represented by two quadratic approximate curve expressions obtained by one discharge.

FIG. 13 is a graph for explaining how to determine two arbitrary points on two approximate characteristic curves.

FIG. 14 is a graph for explaining how to determine an assumed point with respect to a point defined in one approximate characteristic curve and how to correct a slope between two points.

FIG. 15 is a graph for explaining how to determine an assumed point with respect to a point defined in the other approximate characteristic curve and how to correct a slope between two points.

FIG. 16 is an explanatory diagram showing, in partial blocks, a schematic configuration of a battery state-of-charge measuring apparatus according to an embodiment of the present invention to which the method for calculating a correction coefficient for detecting the state of charge of a battery of the present invention is applied.

FIG. 17 is a flowchart illustrating a main routine of a process performed by a CPU according to a control program stored in a ROM of the microcomputer in FIG. 16;

FIG. 18 is a flowchart showing a main routine of a process performed by a CPU according to a control program stored in a ROM of the microcomputer of FIG.

FIG. 19 is a flowchart of a subroutine showing an open circuit voltage update process of FIG. 17 in accordance with a first concept of battery open circuit voltage measurement.

20 is a graph used to explain how to update the assumed open circuit voltage in the open circuit voltage update process of the flowchart of FIG. 19;

21 is a flowchart of a subroutine showing an open circuit voltage update process of FIG. 17 according to a second concept of battery open circuit voltage measurement.

FIG. 22 is a flowchart of a subroutine showing an open circuit voltage update process of FIG. 17 in accordance with a third concept of battery open circuit voltage measurement.

FIG. 23 is a graph showing a linear correlation established between the amount of electricity (Ah) of the battery and the open circuit voltage.

FIG. 24 is a flowchart of a subroutine showing a pure resistance calculation process of FIG. 17;

FIG. 25 is a graph of an open circuit voltage-pure resistance characteristic showing a correlation between a pure resistance and an open circuit voltage in a static state of the battery of FIG. 16;

FIG. 26 is a flowchart of a subroutine showing an open circuit voltage calculation process during charging in FIG. 18;

FIG. 27 is a graph showing a change over time of a charge / discharge current generated in the battery of FIG. 17;

FIG. 28 is a graph for explaining how to determine two points on two approximate characteristic curves in another procedure for measuring the pure resistance of the battery.

FIG. 29 is a graph for explaining how to determine an assumed point with respect to a point defined in one of the approximate characteristic curves and how to correct a slope between two points in another procedure for measuring the pure resistance of the battery. .

FIG. 30 is a graph for explaining how to determine an assumed point with respect to a point defined in the other approximate characteristic curve and how to correct a slope between two points in another procedure for measuring the pure resistance of the battery. .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 13 Battery 23 Microcomputer 23a CPU 23b RAM 23c ROM 23A Pure resistance measuring means 23B Open circuit voltage measuring means 23C Static pure resistance value determining means 23D Computing means 23E Approximate curve equation computing means 23F Second computing means 23G Open voltage measuring means 23H approximate expression determining means 23J arithmetic control means 23K second open-circuit voltage measuring means 23L second approximate expression determining means 23M calculating means 23bA storing means 27 characteristic storing means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shuji Satake 1500 Yasushi Sogyo Co., Ltd. Tomohiro 1500 Onjuku, Susono City, Shizuoka Prefecture Yazaki Sogyo Co., Ltd.F-term (reference) FF42 FF43 FF44 5H115 PA08 PG04 PI16 SE06 TI01 TI02 TI05 TI06 TR19 TU11

Claims (22)

[Claims] 1. A terminal voltage in an equilibrium state of a battery that supplies power to a load of a vehicle, based on a charging current and a discharging current of the battery and a terminal voltage periodically measured during charging and discharging of the battery. An open circuit voltage corresponding to the state of the battery is calculated based on the open circuit voltage calculated during the charging and discharging of the battery. The value in the static state is obtained by correcting the value in the static state by a correction coefficient corresponding to the difference between the current state and the static state of the battery in accordance with the current deterioration degree and the current temperature of the battery. A method of calculating the correction coefficient corresponding to the current state of the battery when detecting a value indicating the state of the battery regarding the actual charge capacity, The open circuit voltage-pure resistance characteristic indicating the correlation between the pure resistance in the static state of the battery and the open circuit voltage of the battery is determined in advance, and the battery is charged at least immediately before discharging. When a constant load discharge with a current value sufficient to eliminate the side polarization is performed, based on the terminal voltage and the discharge current of the battery periodically measured, corresponding to a state related to the actual charge capacity of the battery. The present open resistance of the battery is obtained based on the terminal voltage of the battery measured before the start of the constant load discharge, and the current open circuit voltage of the battery is obtained. The value of the pure resistance in the static state of the battery corresponding to the circuit voltage is determined from the predetermined open circuit voltage-pure resistance characteristic, and the current value of the obtained battery is determined. And values of the pure resistance in the static state of the batteries indexing the corresponding open circuit voltage,
The value obtained by dividing the difference value between the current pure resistance value of the battery and the current pure resistance value obtained at the time of the constant load discharge of the battery by the determined pure resistance value in the static state of the battery is A method for calculating a correction coefficient for detecting a charged capacity state of a battery, wherein the correction coefficient is calculated as the correction coefficient corresponding to a current state of the battery. 2. The battery according to claim 1, wherein the battery is periodically measured when the battery performs a constant load discharge at a current value sufficient to eliminate at least a charge-side polarization generated in the battery immediately before discharging. From the terminal voltage and the discharge current, a first approximation curve expression of the voltage-current characteristic showing a correlation between the terminal voltage and the discharge current of the battery during the increase of the discharge current, and the battery of the battery during the decrease of the discharge current The second of the voltage-current characteristics showing the correlation between the terminal voltage and the discharge current.
And a first point on the voltage-current characteristic curve represented by the first approximate curve equation
A second point is defined on the voltage-current characteristic curve represented by the approximate curve equation of
Causing a second voltage drop when the discharge current of
A first assumed point having the same resistance value as a second combined resistance consisting of the pure resistance of the battery and a second polarization resistance component is defined as:
It is assumed on a voltage-current characteristic curve represented by the first approximation curve equation and a first point corresponding to the first point.
Causing a first voltage drop when the discharge current of
A second assumed point having the same resistance value as the first combined resistance consisting of the pure resistance of the battery and the first polarization resistance component,
Assuming on a voltage-current characteristic curve represented by the second approximate curve equation, a first slope of a straight line connecting the second point and the first assumed point is represented by the second discharge current. And the discharge current at the first assumed point, the amount of voltage drop caused by the second polarization resistance component is corrected, and the voltage drop by the second polarization resistance component is removed. A first correction slope is obtained, and a second slope of a straight line connecting the first point and the second assumed point is defined as the first discharge current and the discharge current at the second assumed point. The second correction slope excluding the voltage drop due to the first polarization resistance component is corrected by correcting the amount corresponding to the difference between the voltage drops due to the first polarization resistance component. By calculating the average slope by averaging the first and second slopes, The average slope charge capacity state detection correction coefficient calculation method according to claim 1, wherein the batteries so as to obtain as current pure resistance of the battery was determined. 3. The terminal voltage and the discharge current of the battery measured for the first point and the second point to obtain the first approximate curve equation and the second approximate curve equation are present. 3. The method according to claim 2, wherein the correction coefficient is an arbitrary point within the range. 4. A method according to claim 1, wherein the first point and the second point are defined by the first approximate curve expression and the second approximate curve expression on the first approximate curve expression and the second approximate curve expression. The method according to claim 2 or 3, wherein a point corresponding to a maximum current value of the battery discharge current measured for obtaining the equation is used. 5. When obtaining the first approximate curve equation and the second approximate curve equation, the terminal voltage and discharge current of the battery measured periodically are collected and stored for the latest predetermined time, 5. The method according to claim 2, wherein the information is stored.
A method for calculating a correction coefficient for detecting a charged capacity state of a battery according to the present invention. 6. After the charging or discharging of the battery is completed, the open-circuit voltage of the battery is measured a plurality of times during a predetermined time after a predetermined time has passed, and the measured open-circuit voltage and Based on the difference value with the assumed open circuit voltage, a predetermined power approximate expression having a negative power is determined, and the power of the determined power approximate expression becomes -0.5 or approximately-
Until 0.5, the power approximation is repeatedly determined while updating the assumed open circuit voltage, and when the exponent becomes -0.5 or becomes approximately -0.5. 6. The method according to claim 1, wherein the assumed open circuit voltage is obtained as a current open circuit voltage of the battery. 7. When the measured open circuit voltage is obtained after the end of charging of the battery, the time approximation is represented by t, an unknown coefficient α, and an unknown negative exponent D. 7. The method according to claim 6, wherein the equation is represented by α · t ^D. 8. When the measured open-circuit voltage is obtained after the end of discharging of the battery, the value for determining the power-approximation equation is calculated based on the assumed open-circuit voltage from the measured open-circuit voltage. The absolute value of the value obtained by subtracting the circuit voltage, where t is the time, α is the unknown coefficient, and D is the unknown negative power.
7. The method according to claim 6, wherein the power approximation formula is represented by α · t ^D. 9. The open-circuit voltage measured during the fixed time is set to an arbitrary number of 2 or more, and the open-circuit voltage obtained by the measurement and the time from the end of charge / discharge are regression-calculated. 9. The method according to claim 7, wherein the exponent D of the power approximation formula is determined. 10. A method in which the open-circuit voltage of the battery is increased a plurality of times during a period of time from when the charging or discharging of the battery is completed to a predetermined second time. Measuring, from the measured open-circuit voltage, the open-circuit voltage and the charge relating to a period from the end of the first time to the end of the second time after charging or discharging of the battery is completed. Or, indicating a correlation with the elapsed time from the end of the discharge, determine a predetermined linear approximation formula,
A predetermined third time longer than the second time,
5. The solution of the determined straight-line approximation formula when substituted as the elapsed time from the end of charging or discharging of the battery is obtained as the current open circuit voltage of the battery. Or a method of calculating a correction coefficient for detecting a charged capacity state of a battery according to 5. 11. The linear approximation formula is represented by c · t + E, where t is an elapsed time from the end of charging or discharging of the battery, c is an unknown coefficient, and E is an unknown complement. Calculation method of the correction coefficient for detecting the charged capacity state of the battery. 12. A terminal voltage in an equilibrium state of the battery based on a charging current and a discharging current of the battery and a terminal voltage which are periodically measured during charging and discharging of the battery for supplying power to a load of the vehicle. An open circuit voltage corresponding to the state of the battery is calculated based on the open circuit voltage calculated during the charging and discharging of the battery. The value in the static state is obtained by correcting the value in the static state by a correction coefficient corresponding to the difference between the current state and the static state of the battery in accordance with the current deterioration degree and the current temperature of the battery. By detecting the value indicating the state related to the actual charge capacity of the battery, by calculating the correction coefficient according to the current state of the battery, Open circuit voltage-pure resistance characteristics indicating a correlation between a pure resistance in a static state of the battery and an open circuit voltage of the battery, and characteristic storage means in which the battery is stored in advance. When a constant load discharge is performed with a current value sufficient to eliminate the charging-side polarization that has occurred, the actual charge of the battery is performed based on the terminal voltage and the discharge current of the battery that are periodically measured. A pure resistance measuring means for obtaining a current pure resistance of the battery corresponding to a state relating to a capacity; anda current open circuit voltage of the battery based on a terminal voltage of the battery measured before the start of the constant load discharge. Open circuit voltage measuring means to be determined; pure resistance in a static state of the battery corresponding to the current open circuit voltage of the battery determined by the open circuit voltage measuring means Is calculated from the open circuit voltage-pure resistance characteristic stored in the characteristic storage means, and the open pure voltage is calculated by the static pure resistance value calculating means. The value of the pure resistance in the static state of the battery corresponding to the current open circuit voltage of the battery obtained by the circuit voltage measuring means, and the value of the pure resistance obtained by the pure resistance measuring means during the constant load discharge of the battery. The difference value between the current pure resistance value of the battery and the current open circuit voltage of the battery determined by the open circuit voltage measuring means, which is determined by the static pure resistance value determining means, is calculated. Calculating means for calculating a value obtained by dividing the value of the pure resistance in a static state of the battery, wherein the value calculated by the calculating means is calculated as the correction coefficient corresponding to the current state of the battery. Charge capacity state detection correction coefficient calculation unit battery according to claim. 13. The pure resistance measuring means periodically measures at the time of constant load discharge at a current value sufficient to eliminate the charging side polarization of the battery at least immediately before discharge of the battery. A first approximation curve expression of the voltage-current characteristic showing a correlation between the terminal voltage of the battery and the discharge current during the increase of the discharge current from the terminal voltage of the battery and the discharge current; An approximate curve expression calculating means for obtaining a second approximate curve expression of the voltage-current characteristic indicating a correlation between a terminal voltage of the battery and a discharge current, and a voltage-current represented by the second approximate curve expression A first combined resistance consisting of a pure resistance of the battery and a first polarization resistance component, which causes a second voltage drop when a second discharge current corresponding to a second point defined on the characteristic curve flows; Same as A first assumed point having a resistance value is assumed on a voltage-current characteristic curve represented by the first approximate curve equation, and a first assumed point having a resistance value is defined on a voltage-current characteristic curve represented by the first approximate curve equation. The same resistance as the second combined resistance consisting of the pure resistance of the battery and the second polarization resistance component that causes a first voltage drop when a first discharge current corresponding to the first point defined in A second assumed point having a value is assumed on a voltage-current characteristic curve represented by the second approximate curve equation, and a first straight line connecting the second point and the first assumed point is assumed. Is corrected by an amount corresponding to a difference in voltage drop due to the second polarization resistance component, which is caused by the second discharge current and the discharge current at the second assumed point, respectively. Obtain a first correction slope excluding the voltage drop due to the polarization resistance component In both cases, the first slope, which is caused by the first discharge current and the discharge current at the second assumed point, forms a second slope of a straight line connecting the first point and the second assumed point. Is corrected by the amount corresponding to the difference in voltage drop due to the polarization resistance component of
A second correction means for obtaining a second correction slope excluding a voltage drop due to the polarization resistance component of the second calculation slope, and averaging the obtained first correction slope and the second correction slope to obtain an average slope. 2. The battery according to claim 1, wherein the average slope obtained by the second calculation means is obtained as a current pure resistance of the battery.
3. The correction coefficient calculation device for detecting a charged capacity state of a battery according to 2. 14. The terminal voltage and discharge current of the battery measured at the first point and the second point to obtain the first approximate curve equation and the second approximate curve equation. 14. The correction coefficient calculating device according to claim 13, wherein the correction coefficient is an arbitrary point within the range. 15. The first approximate curve expression and the second approximate curve on the first approximate curve expression and the second approximate curve expression based on the first point and the second point. 15. The battery charge capacity state detection correction coefficient calculating device according to claim 13 or 14, wherein the point corresponds to a maximum current value of the battery discharge current measured for obtaining the equation. 16. The approximate curve expression calculating means, wherein
In order to obtain the approximate curve equation of the above and the second approximate curve equation,
A storage means for collecting, storing, and storing terminal voltage and discharge current of the battery periodically measured during a constant load discharge of the battery for a predetermined latest time.
16. The correction coefficient calculating device for detecting a charged capacity state of a battery according to 4 or 15. 17. The open-circuit voltage measuring means for measuring the open-circuit voltage of the battery during a predetermined time after a predetermined time has elapsed after the charging or discharging of the battery has been completed. Means and an approximation for determining a predetermined power-of-power approximation formula whose power is negative by a difference value between a plurality of open-circuit voltages measured by the open-circuit voltage measuring means a plurality of times and an assumed open circuit voltage. Expression determining means and determining the power approximate expression until the power of the power approximate expression determined by the approximate expression determining means becomes -0.5 or approximately -0.5. Means for updating the assumed open circuit voltage and repeatedly executing the same, wherein the exponent is -0.5 or approximately -0.5.
And calculating the assumed open circuit voltage at the time when the battery current becomes the current open circuit voltage of the battery.
The correction coefficient calculating device for detecting a charged capacity state of a battery according to 4, 15 or 16. 18. When the measured open-circuit voltage is obtained after the charging of the battery is completed, the time is t, the unknown coefficient is α, and the unknown negative power is D. 18. The correction coefficient calculating device for detecting a state of charge of a battery according to claim 17, wherein the approximate expression is represented by α · t ^D. 19. The battery according to claim 19, wherein the measured open circuit voltage is
The exponential approximation
The value for determining the formula is the measured open circuit voltage.
The absolute value of the value obtained by subtracting the assumed open circuit voltage from
Yes, time is t, unknown coefficient is α, unknown negative power
D, the power approximation equation is α · t ^D Claim represented by
Item 18. Battery charge capacity state detection correction coefficient calculation according to item 17.
Output device. 20. The approximation formula determining means performs a regression calculation process on an arbitrary number of two or more open voltages measured during the fixed time by the open voltage measuring means and a time from the end of charge / discharge. 2. The power exponent D of a power approximation formula is determined.
20. The correction coefficient calculating device for detecting a charged capacity state of a battery according to 8 or 19. 21. The open circuit voltage measuring means according to claim 1, wherein an elapsed time after the charging or discharging of said battery is completed from a predetermined first time to a predetermined second time. A second open-circuit voltage measuring means for measuring the open-circuit voltage of the battery; and a plurality of open-circuit voltages obtained by measuring the open-circuit voltage a plurality of times by the second open-circuit voltage measuring means. A second linear approximation formula that determines a predetermined linear approximation that indicates a correlation between the open-circuit voltage and the elapsed time from the end of the charging or discharging, with respect to a period from when time elapses to when the second time elapses. Determined by the approximate expression determining means and the second approximate expression determining means when a predetermined third time longer than the second time is substituted as the elapsed time from the end of the charging or discharging. Calculation to calculate the solution of the linear approximation formula 17. The correction coefficient calculating apparatus for detecting a charged capacity state of a battery according to claim 12, wherein the solution calculated by the calculating means is obtained as a current open circuit voltage of the battery. . 22. The linear approximation formula is represented by c · t + E, where t is an elapsed time from the end of charging or discharging of the battery, c is an unknown coefficient, and E is an unknown complement. The correction coefficient calculating device for detecting the charged capacity state of the battery of the present invention.