JP4514449B2 - Method for determining remaining capacity of secondary storage battery, method and apparatus for detecting remaining capacity of secondary battery mounted on vehicle using determination result, and terminal for determining remaining capacity of secondary storage battery Method and apparatus for determining slope and intercept used to calculate voltage - Google Patents

Description

The present invention uses a method for determining the remaining capacity (remaining life or deterioration state) or state of charge (SOC) of a secondary storage battery in a vehicle equipped with a secondary storage battery such as a lead storage battery, and a determination result using the method. The present invention relates to a method and an apparatus for detecting a remaining capacity of a secondary battery mounted on a vehicle.
The present invention also relates to a method and an apparatus for obtaining a slope and an intercept used for calculating a terminal voltage for determining a remaining capacity of a secondary storage battery.

It is very useful to be able to detect in advance the remaining capacity or SOC of a secondary storage battery such as a lead storage battery mounted on a vehicle such as a passenger car.
For example, if the remaining life of an in-vehicle secondary storage battery can be detected at an appropriate timing, the secondary storage battery can be replaced at an appropriate timing, and the life of the secondary storage battery is exhausted or the remaining capacity and SOC are insufficient, causing the vehicle to restart. It is possible to prevent the operation from becoming impossible.

  In order to reduce environmental pollution and improve vehicle fuel efficiency, the vehicle has an idling stop function that stops the internal combustion engine (engine), such as when the vehicle is temporarily stopped at an intersection to wait for a signal or when it is stopped due to traffic jams. The vehicles that have them are being put into practical use. When performing such an idling stop, it is necessary to know that the in-vehicle secondary storage battery has a remaining capacity as much as possible after restarting the vehicle after the idling stop, or to know the deterioration state of the secondary storage battery.

Storage batteries such as lead storage batteries are frequently used as such secondary storage batteries. A conventional method and apparatus for determining the state of the storage battery such as the remaining capacity of the storage battery or the SOC when the storage battery is mounted on a vehicle will be described below.
Various methods for measuring the remaining capacity of a storage battery have been tried. Hereinafter, an overview of a conventional method for measuring the remaining capacity of a storage battery will be given.

Since lead acid batteries produce water by discharging and produce sulfuric acid by charging, the specific gravity of the sulfuric acid aqueous solution is reduced when discharged, and the specific gravity of the sulfuric acid aqueous solution is restored by charging. Using this phenomenon, a method of estimating the remaining capacity of a lead storage battery using the specific gravity of the electrolyte as an index is known.
However, since the concentration distribution of the electrolyte contained in the lead storage battery often becomes non-uniform, this method cannot always accurately estimate the remaining capacity of the lead storage battery. In recent years, sealed lead-acid batteries with very little electrolyte have been adopted. For such a sealed lead-acid battery, it is difficult to measure the specific gravity of the electrolyte itself, so the remaining capacity of the lead-acid battery cannot be estimated.

Japanese Patent Laid-Open No. 53-127646 discloses a technique for calculating the output impedance of a battery from the relationship between the starter current during starter cranking and the battery terminal voltage, and detecting the state of the battery from this output impedance. .
More specifically, Japanese Patent Laid-Open No. 53-127646 discloses (1) the transient current value of the alternator generated when the engine start key is turned between the alternator and the in-vehicle lead acid battery (battery). Measured as the current flowing through the resistor interposed in the battery, further measured the terminal voltage of the battery, calculated the output impedance by calculating these measurement results with an operational amplifier, from the obtained output impedance of the battery just before the vehicle traveled Disclosed is a method for obtaining an initial remaining capacity, (2) further obtaining a charge amount or charge / discharge amount while the vehicle is running, and (3) calculating a remaining battery capacity by comparing the initial remaining capacity and the charge / discharge amount. Yes.
However, since the output impedance changes greatly due to the influence of polarization in the battery, the state of the battery cannot be determined using the output impedance that changes greatly. It is sufficient to wait until the output impedance is stabilized. However, in order to wait until the output impedance is stabilized, the vehicle needs to be stopped for several hours or more, which is not practical.

Japanese Laid-Open Patent Publication No. 1-129177 discloses an invention obtained by improving the method described in Japanese Laid-Open Patent Publication No. 53-127646. In the method described in Japanese Patent Laid-Open No. 1-129177, focusing on the fact that the output impedance is stabilized when the change in the open circuit voltage (open circuit voltage) of the battery is reduced, the open circuit voltage of the battery when the vehicle is stopped. This is a method of detecting the state of the battery using the output impedance in that state by detecting that the change in the battery has become below a predetermined value.
However, even if only the output impedance calculated in this way is used, the state of the battery cannot be detected sufficiently accurately, and in any case, it is necessary to wait until the polarization of the battery becomes stable. Therefore, a method for detecting the state of the battery in a shorter time is desired.

Japanese Patent Laid-Open No. 63-27776 (1) actually measures the terminal voltage drop of the battery relative to the amount of discharge charge during engine start-up in a new battery when the battery is first installed in the vehicle, and (2) The engine is starting every time the vehicle travels, provided that the time required for battery characteristics to recover (polarization stabilizes) has elapsed between engine stop and start, and that the remaining battery capacity is greater than or equal to a predetermined value. (3) Disclosed is a method for predicting the battery life by calculating the terminal voltage drop of the battery with respect to the amount of discharge charge and calculating using the initial voltage drop and the voltage drop after running. .
As described above, this method also has to wait until the polarization of the battery is stabilized, and the state of the battery cannot be accurately detected even using only the voltage drop.

  JP-A-1-39068 (1) detects the discharge current of a battery at a plurality of time points indicating different values during a large current discharge such as when the starter is started, and the terminal voltage of the battery when each discharge current flows out. (2) The internal resistance value and power of the battery are calculated from the detected current and voltage values, and (3) calculated using a function representing the correlation between the battery capacity, the internal resistance, and the electromotive force obtained experimentally in advance. Discloses a method for detecting the state of the battery from the internal resistance and the electromotive force. However, this method cannot accurately detect the state of the battery, and the processing of this method is complicated.

As another example developed as a short-time inspection method for a storage battery, a method for measuring the internal impedance of the storage battery is known.
For example, Japanese Patent No. 2536257 (Japanese Patent Laid-Open No. 4-95788) discloses an invention that uses an internal impedance to detect the remaining capacity of a lead-acid battery. In the present invention, (1) the internal impedance of the lead storage battery is measured, and (2) the measured internal impedance of the lead storage battery is converted into an inductance component L, an electrolyte resistance RΩ, a charge transfer resistance Rct, and an electric double layer capacity. Apply an equivalent circuit consisting of Cd, Warburg impedance W, and Warburg coefficient σ to find an optimal solution. (3) Compare at least one of L, RΩ, Rct, Cd, W, and σ with the initial value, The life of the lead storage battery is determined from the difference.
However, when this invention is used for the inspection of the state of the lead storage battery mounted on the vehicle, the influence on the lead storage battery from the generator operating as the engine rotates, the load fluctuation of the equipment mounted on the vehicle, etc. It is difficult to measure the internal impedance of lead-acid batteries under the influence. If the internal impedance of the lead-acid battery cannot be measured, it cannot be compared with the initial value and the life cannot be determined.
Further, when the present invention is implemented, the configuration of the measuring apparatus is complicated, the size is increased, and the price is increased.

Further, as another example developed as a short-time inspection method for a storage battery, the current value discharged or charged from the storage battery is constantly measured, and the current measurement value is integrated to determine the remaining capacity or SOC of the storage battery. A method (hereinafter referred to as “current integration method”) is known.
The current integration method has a problem in that the error in the integrated value gradually increases due to the measurement error in the current value, and the state of the storage battery cannot be obtained accurately.

  For this reason, methods that improve the “current integration method” have been proposed in Japanese Patent No. 2791751 (Japanese Patent Laid-Open No. 8-19103), Japanese Patent Laid-Open No. 9-71065, and the like.

The invention of Japanese Patent No. 2791751 is a method of measuring the remaining capacity of a lead storage battery for an electric vehicle by processing data using both the current integration method and the internal resistance detection method, and calculating the remaining capacity of the storage battery by the current integration method. A technique for correcting the remaining capacity. That is, (1) First, the remaining capacity of a lead storage battery mounted on an electric vehicle is calculated by a current integration method. (2) Further, when the full charge of the lead storage battery for an electric vehicle is completed and when the vehicle is temporarily stopped The internal impedance of the lead storage battery is measured, and (3) the value of the remaining capacity of the storage battery obtained by the current integration method is corrected by the discharge rate derived from the internal impedance.
Thus, the correction remaining capacity is calculated by preparing a terminal voltage and remaining capacity data table in constant current discharge at a specific discharge current value in advance, and the specific discharge current value continues for a certain period of time while the vehicle is running. This is detected, the terminal voltage of the storage battery at that time is measured, and the remaining terminal capacity of the storage battery for correction is obtained by referring to the measured terminal voltage in the data table. Then, the remaining capacity of the current integration method obtained in advance is corrected with the calculated remaining capacity for correction.
This method is useful as a method for inspecting the remaining capacity of a storage battery for automobiles, and is an important technique in an electric vehicle that needs to know the remaining capacity of a lead storage battery accurately.
However, according to the present invention, in addition to the measurement by the current integration method, it is also necessary to perform the measurement by the internal impedance. When a measuring device that realizes this method is manufactured, the device price becomes high. In particular, according to the present invention, it is difficult to measure the internal impedance described above.

The invention disclosed in Japanese Patent Laid-Open No. 9-171655 is a technique suitable for measuring the remaining capacity of a storage battery (battery) mounted on an electric vehicle such as an electric vehicle. The reason for this is that in an electric vehicle, there are many opportunities to obtain the remaining capacity of the storage battery by setting the discharge current value at the travel speed normally used by the vehicle as the specific discharge current value.
However, the invention disclosed in Japanese Patent Application Laid-Open No. 9-171065 is not suitable for the remaining capacity of a storage battery mounted on a vehicle (normal automobile) operating with an internal combustion engine. The reason for this is that in ordinary cars, there are few opportunities for specific current values that frequently continue for a certain period of time while the car is running, so there are very few opportunities to determine the remaining capacity of the storage battery, so the This is because the capacity cannot be obtained.

As a method for solving the above-described problem of the invention disclosed in Japanese Patent Laid-Open No. 9-171655, for example, a plurality of terminal voltage and remaining capacity data tables are prepared, and the remaining capacity is determined by a plurality of current values. Is also possible.
However, in order to implement such a method, it is necessary to prepare a plurality of data tables, and the processing becomes complicated. In order to accurately measure the remaining capacity, if the relationship between the terminal voltage of the storage battery and the remaining capacity changes depending on the temperature and the deterioration state, it is necessary to prepare more data tables accordingly. It is assumed that a complicated device is required to store and process the data. In addition, it is troublesome to create such a large amount of data. It is also difficult to judge the deterioration state of the storage battery.

JP-A-53-127646 Japanese Patent Laid-Open No. 1-129177 JP 63-27776 A JP-A-1-39068 Japanese Patent No. 2536257 Japanese Patent No. 2791751 (JP-A-8-19103) Japanese Patent Laid-Open No. 9-171065

In order to apply the conventional technology as described above to a method for measuring the remaining capacity of a storage battery mounted on a vehicle, the conventional technology has a problem that a reliable determination cannot be made.
For example, in the current integration method, the remaining capacity or SOC of the storage battery is determined by another method at an appropriate timing, and the measured value and the remaining capacity or SOC obtained by integration of the current are referred to each other, There is a need to develop a method for correcting the remaining capacity or SOC.

An object of the present invention is to provide a method capable of determining the remaining capacity or SOC of a secondary storage battery with high accuracy.
Another object of the present invention is to provide a method and apparatus capable of determining in real time the remaining capacity or SOC of a secondary storage battery mounted on a vehicle or the like by a simple method.
A further object of the present invention is to provide a method and apparatus for determining the slope and intercept used to calculate the terminal voltage for determining the remaining capacity of the secondary storage battery.

The inventor of the present application has found that the remaining capacity or SOC of the secondary storage battery can be defined by the terminal voltage and that it is defined as a primary expression in the relationship between the terminal voltage and the discharge current.
In determining the remaining capacity or SOC when such a secondary storage battery is mounted on a vehicle, a determination error may occur if the measured inter- terminal voltage of the secondary storage battery is used as it is. Therefore, to measure the discharge current of the actual secondary storage battery, the measured discharge current seek operation terminal voltage which is calculated by introducing the relational expression is defined as a primary expression above, further, found a voltage between its operational terminal The remaining capacity or SOC of the in-vehicle secondary storage battery is determined from the voltage between the terminals.

Further, the inventor of the present application uses accuracy when obtaining the slope and intercept in the relational expression (primary expression) between the terminal voltage and the discharge current for determining the remaining capacity or SOC of the secondary storage battery not affected by the load or the like. I found a way to increase it.
Of course, the work (processing) for obtaining the slope and intercept in the relational expression (primary expression) does not require real-time characteristics, and therefore may take some time, and the above-described method, for example, the current integration method or the like is applied. You can also.

According to the present invention , V _SOC = a _SOC × I _j + b _SOC (V _SOC is a calculation obtained by calculation in each remaining capacity or each SOC of the secondary storage battery, which is used to determine the remaining capacity or SOC of the secondary storage battery. A voltage between terminals, I _j is a discharge current, a _SOC is a first coefficient that means a slope, and b _SOC is a second coefficient that means an intercept). A method for determining a first coefficient and a second coefficient,
As a first discharge characteristic test, in each remaining capacity or each SOC of the secondary storage battery, a first discharge in which the terminal voltage of the secondary storage battery is stabilized by a plurality of first discharge currents (I _j ) whose values are sequentially decreased. discharge during the time, the first step, a plurality of sets of terminals obtained by the measurement in each of the remaining capacity or the respective SOC measuring the inter-terminal voltage of the secondary battery in the first discharge characteristic test wherein a between voltages from the respective first discharge current, the in each remaining capacity or the respective SOC, the first coefficient (a _SOC) and determined Mel second step, a second discharge characteristic test, the secondary constant current discharge battery from a fully charged state at a second discharge current, and a third step of measuring the inter-terminal voltage of the secondary battery in the second discharge characteristic test, obtained by the second discharge characteristics test each residual volume was measured during the time course Or the inter-terminal voltage at each SOC, by introducing a first coefficient determined the a discharge current to the primary equation, a fourth step of obtaining the second coefficient in the remaining capacity or the SOC (b _SOC) Having
There is provided a method for obtaining a first coefficient and a second coefficient used for calculating a voltage between calculation terminals used for determining a remaining capacity or SOC of a secondary storage battery .

Preferably, in the first discharge characteristic test in the first step, in order to perform the first discharge characteristic test in the next remaining capacity or the next SOC, after the current first discharge characteristic test, a predetermined discharge current is used. An adjustment discharge is performed to discharge and adjust to the next remaining capacity or the next SOC value.

Preferably, at the time of full charge of the secondary storage battery in the third step , each of the fixed first discharge currents (I1 to I4) is discharged only during the first discharge time (T11, T12), A first measurement step of measuring the voltage between the terminals at this time, a first adjustment step of adjusting the discharge capacity by continuing constant current discharge at a constant second discharge current in the third step for an arbitrary time, A repetitive step of repeating the first measurement step and the first adjustment step until a terminal voltage of the secondary storage battery becomes a specified minimum voltage (V ₀ ) or less during the first adjustment step; and the secondary storage battery when the inter-terminal voltage falls below the prescribed minimum voltage (V _0), a discharge is discharged by a sum of products of the constant and the plurality of first current the first discharge period of time the first measuring step capacity and the first measurement step in the iteration step A first discharge capacity is defined by the product of the number of times was performed (n), the terminal voltage of said secondary battery in the first adjustment step is performed repeatedly until drops until said prescribed minimum voltage (V _0), a second discharge capacity is defined by the product of the total time and the constant second discharge current of time constant current discharging at the constant second discharge current, the first discharge capacity and the second discharge capacity The step of defining the total third discharge capacity as the total discharge capacity (Q1) of the secondary storage battery, and the discharge capacity by the second discharge current and the first measurement before performing the first measurement steps. For each remaining capacity obtained by subtracting the total capacity of the discharge capacity discharged in the process from the total discharge capacity (Q1) of the secondary storage battery, a plurality of sets of inter-terminal voltages and the first discharges obtained by the measurement are obtained. wherein the current first coefficient (a _SOC ) And the determined Mel first coefficient calculating step, for each remaining capacity of the secondary battery for obtaining the first coefficient (a _SOC) percentage (An) to the time of obtaining the first coefficient (a _SOC) and determined Mel steps from a total discharge capacity (Q1) of each remaining capacity of the secondary battery and the secondary battery, the secondary battery or the secondary battery and the capacity and charge-discharge characteristics of the same other two, A second measurement step of measuring the inter-terminal voltage at this time by discharging the secondary storage battery at a predetermined third current (Id3) for a predetermined discharge time until it drops to a predetermined inter-terminal voltage when fully charged; , a fourth discharge capacity is defined by the product of said third current (Id3) and the discharge time (T3) defined as the total discharge capacity (Q2), wherein the percentage (Bn) of the total discharge capacity (Q2) Obtain the relationship with the voltage between the terminals, the result, the obtained first coefficient and the discharge current And a second coefficient calculation step for _obtaining the second coefficient (b _SOC ) in each remaining capacity or each SOC by introducing each first discharge current into the linear equation .

Preferably, the results showing the relationship between the terminal voltage and the percentage (Bn) of the total discharge capacity (Q2), between the terminals when the the percentage according to claim 1 (An) matching percentage and (Bn) A step of obtaining a voltage (Vn) and the discharge current (Id3).

Preferably, from the first coefficient indicating the slope of the linear expression, the voltage (Vn) between the terminals at the time of the percentage (Bn), and the discharge current (Id3), in each remaining capacity or each SOC, A step of _obtaining the second coefficient (b _SOC ), which means an intercept of the linear expression .

According to the present invention, the obtained by the method according to any, of each remaining capacity or the SOC, the first coefficient (a _SOC) and the respective remaining capacity or the said second coefficient (b _SOC) A table corresponding to each SOC , the remaining capacity or SOC having the same capacity and charge / discharge characteristics as the secondary storage battery for which the first coefficient (a _SOC ) and the second coefficient (b _SOC ) were obtained. and measuring the discharge current and the terminal voltage of the secondary battery to be judged, and the discharge current was the measurement, and the tabled said first coefficient (a _SOC) and the second coefficient (b _SOC) Introduced into the relational expression, the inter- operation terminal voltage (V _SOC ) is calculated, and the remaining capacity or SOC is determined by comparing and comparing the measured inter- terminal voltage and the calculated inter- operation terminal voltage (V _SOC ). the remaining capacity or SOC of should do secondary battery Determining, method of determining the remaining capacity of the secondary battery is provided.
Preferably, when the measured inter-terminal voltage is located between two adjacent ones of the calculation inter-terminal voltages, a corresponding inter-terminal voltage is calculated by interpolation, and the remaining voltage is calculated based on the calculated inter-terminal voltage. The remaining capacity or SOC of the secondary storage battery whose capacity or SOC is to be determined is determined.

Further, according to the present invention, a linear expression that associates each remaining capacity of the secondary storage battery or the discharge current (I _j ) in each SOC with the voltage (V _SOC ) between the calculation terminals at that time by any one of the methods described above. , V _SOC = a _SOC × I _j + b _SOC (where V _SOC is a voltage between operation terminals , I _j is a discharge current, a _SOC is a first coefficient _indicating a slope , and b _SOC is a second coefficient _indicating an intercept. Obtaining a first coefficient and a second coefficient in
When a secondary storage battery having the same capacity and the same charge / discharge characteristics as the secondary storage battery and whose remaining capacity or SOC is to be determined is mounted on a vehicle, between the terminals of the secondary storage battery whose remaining capacity or SOC should be determined Measuring voltage and discharge current;
Introducing the measured discharge current and the first coefficient and the second coefficient into the linear equation to determine the inter- operation terminal voltage (V _SOC );
Comparing the measured inter- terminal voltage and the calculated inter- operation terminal voltage to determine the remaining capacity or SOC of the secondary storage battery to determine the remaining capacity or SOC mounted on the vehicle,
A method for determining the remaining capacity of a secondary storage battery is provided.

Preferably, in the step of obtaining the first coefficient and the second coefficient in the linear expression , the first coefficient (a _SOC ) and the second coefficient (b _SOC ) and the terminal voltage are associated with each remaining capacity or each SOC. tabulated Te, the discharge current and the terminal voltage of the remaining capacity or said secondary battery to be judged SOC measured, the discharge current was the measurement, the tabled said first coefficient (a _SOC) and The second coefficient (b _SOC ) is introduced into the linear equation to calculate the inter- operation terminal voltage (V _SOC ), and the measured inter- terminal voltage is compared with the calculated inter- operation terminal voltage (V _SOC ). Then, the remaining capacity or SOC of the secondary storage battery for which the remaining capacity or SOC is to be determined is determined.

Preferably, the measured inter-terminal voltage, when located between two adjacent voltage between said operation terminals, calculates the inter-terminal voltage corresponding to the interpolation, on the basis of the inter-terminal voltage the calculated two The remaining capacity or SOC of the secondary storage battery is determined.

Further, according to the present invention, after the remaining capacity or SOC of the secondary storage battery for which the remaining capacity or SOC determined by the method for determining the remaining capacity of any of the secondary storage batteries is to be determined , the vehicle is idling stopped. There is provided a method for determining the remaining capacity of a secondary storage battery for determining whether the remaining capacity or SOC is capable of restarting the vehicle .

According to the present invention, the obtained in either method, a linear equation relating the discharge current in each remaining capacity or the SOC of the secondary battery (I _j) and the inter-terminal voltage at that time (V _SOC), V _SOC = a _SOC × I _j + b _SOC (where V _SOC is a voltage between operation terminals , I _j is a discharge current, a _SOC is a first coefficient, and b _SOC is a second coefficient) . memory means for storing the coefficients in association with each remaining capacity or the SOC, before Symbol secondary storage battery or the to be determined residual capacity or SOC with the same charge and discharge characteristics and the same capacity as the secondary蓄 battery, When the secondary storage battery is mounted on the vehicle, the means for measuring the voltage between the terminals and the discharge current of the secondary storage battery mounted on the vehicle, the measured discharge current, and each remaining capacity in the memory means Or stored in association with each SOC. Comparing and collating a first computing means for obtaining the operation terminal voltage (V _SOC) introducing the first coefficient and the second coefficient to the linear expression, a voltage of the operational inter-terminal voltage between terminals of said measured Thus, there is provided an apparatus for determining a remaining capacity of a secondary storage battery, comprising: a determination means for determining a remaining capacity or SOC of a secondary storage battery for determining a remaining capacity or SOC mounted on the vehicle.
According to the present invention, the remaining capacity or SOC of the secondary storage battery determined by the device for determining the remaining capacity of the secondary storage battery can be restarted after the idling stop of the vehicle. Having means for determining whether or not it is SOC ;
A vehicle having an idling stop function is provided.

In the present invention, a relational expression between the terminal voltage and current in each remaining capacity or SOC of the secondary battery is expressed as a linear equation, and two coefficients obtained by two kinds of discharge characteristic tests as coefficients of the linear equation, that is, Since the first coefficient a _SOC and the second coefficient b _SOC are used, an accurate remaining capacity or SOC can be determined.

When the relational expression thus obtained is used for determination of the remaining capacity or SOC of an in-vehicle secondary storage battery, for example, it is compared with the terminal voltage obtained by calculating the terminal voltage actually measured by the relational expression. Therefore, the remaining capacity or SOC of the in-vehicle secondary storage battery can be accurately determined.
Since the relational expression is a linear expression, the calculation is easy.

Referring to the basic aspects Figure 1 of the present invention describes the basic aspect of the present invention.
FIG. 1 is a diagram illustrating processing steps as a basic form of the present invention.

Step S1: A relational expression between the terminal voltage V _SOC and the discharge current is obtained in advance for a lead storage battery with a known remaining capacity or SOC .
In the first embodiment of the present invention, assuming that each remaining capacity or SOC of a secondary storage battery, for example, a storage battery, is defined as a relational expression between terminal voltage and discharge current, the first coefficient in the following relational expression a _SOC and the second coefficient b _SOC are obtained (step S1).

V _SOC = a _SOC × I + b _SOC
However, V _SOC is at a certain remaining capacity or SOC
Is the terminal voltage of the storage battery,
I is the discharge current,
a _SOC is the first coefficient,
b _SOC is the second coefficient.
... (1)

Remaining capacity or the SOC is the terminal voltage V _SOC in remaining capacity or SOC of the storage battery for a known lead-acid battery can be defined by Equation 1, the secondary battery to be used in other situations, such as the same vehicle as the known remaining capacity or SOC For example, also for a storage battery, the terminal voltage V _SOC can be calculated from the discharge current measured by simple calculation, and the remaining capacity or SOC of the storage battery can be determined using the calculated terminal voltage V _SOC obtained by calculation.
Since the real-time property is not required for the implementation of the method for measuring the remaining capacity or the SOC, a known accurate method for measuring the remaining capacity or the SOC, for example, any of the above-described methods, for example, a method in which the current integration method is improved. Etc. can be applied.

Equation 1 is a simple linear equation, which is easy to calculate. In addition, since the data stored in the memory is basically only the first coefficient a _SOC and the second coefficient b _SOC , the storage amount of the memory is also large. There is an advantage that less.
Measuring the discharge current in this way, determining the terminal voltage V _SOC from the measured discharge current, and determining the remaining capacity or SOC of the storage battery using the terminal voltage V _SOC obtained in principle is subject to various limitations. This is suitable for determining the remaining capacity or SOC of an on-vehicle storage battery.
Therefore, for a storage battery with a known remaining capacity or SOC, a first coefficient and a second coefficient that satisfy Expression 1 are obtained in advance for each remaining capacity or SOC, and Expression 1 is established.
A method for _obtaining the first coefficient a _SOC and the second coefficient b _SOC in Equation 1 will be described later.

Step S2: When the remaining capacity of the actual lead storage battery or the SOC judgment formula 1 is obtained, a storage battery that is the same or equivalent to the storage battery used when obtaining the formula 1 is affected by the load, for example, an in-vehicle storage battery If the discharge current is measured and introduced into Equation 1, in principle, it can be used to determine the remaining capacity of the on-vehicle storage battery or the SOC in real time. Therefore, the following steps S2a to S2c are performed.

Step S2a: Corresponding the first coefficient and the second coefficient of Equation 1 to the terminal voltage V _SOC as preparation work for the determination of the remaining capacity or SOC of the actual lead storage battery, for example, in real time in the data table process For example, the data is stored in a memory unit of the calculation means 10 described later with reference to FIG.

  Although details of steps S2b to S2c will be described later, in this process, the remaining capacity or SOC of the secondary storage battery is calculated.

Step S3: Utilization of the determined remaining capacity or SOC If necessary, based on the determined remaining capacity or SOC, for example, the determination of the replacement time of the lead storage battery or the idling stop process described as the second embodiment, etc. Do.

First Embodiment As a first embodiment of the present invention, referring to FIG. 2, a first coefficient a _SOC and a second coefficient b _SOC satisfying Equation 1 for a battery having a known remaining capacity or SOC in advance The outline of the method for obtaining
FIG. 2 is a process diagram illustrating how to obtain the first coefficient a _SOC and the second coefficient b _SOC in Equation 1.

First coefficient a _SOC calculation step S11: In order to obtain the first coefficient a _SOC of Equation 1, a first discharge characteristic test described with reference to FIG. 3 is performed.

Step S12: The first coefficient a _SOC is obtained from the relationship between the terminal voltage and the discharge current, which is the measurement result of the first discharge test.

Second coefficient b _SOC calculation step S13: In order to obtain the second coefficient b _SOC of Equation 1, a second discharge test is performed on the fully charged storage battery described with reference to FIGS. Find the relationship between discharge time and terminal voltage.

  Step S14: The relationship between the terminal voltage and the discharge current for each remaining capacity or SOC is obtained from the result of the fully charged storage battery obtained in the second discharge test.

Step S15: The second coefficient b _SOC is obtained from the result of step S14.

Details of how to obtain the first coefficient Hereinafter, details of how to obtain the first coefficient a _SOC will be described with reference to FIG.
FIG. 3 is a process diagram illustrating how to obtain the first coefficient a _SOC . Although the steps illustrated in FIG. 3 can be performed manually, in the present embodiment, for example, a case where it is automatically performed using a computer will be described.
When calculating the first coefficient a _SOC and the second coefficient b _SOC , for example, a storage battery having a known (known) characteristic is prepared in accordance with the same or the same standard as an in-vehicle storage battery. Hereinafter, the following processing is performed for the storage battery.

Step S21: The discharge characteristic test repetition index n is initialized to 1.
The discharge characteristic test repetition number index n is an index used to calculate how many times the discharge characteristic test described below is performed and how much is discharged from the storage battery as a result.

Step S22: The discharge current management index j is initialized to 1.
As will be described later with reference to FIG. 4, the discharge current management index j is an index for managing different values of the discharge current I _j when performing a discharge test.

  When the discharge test is manually performed for both the discharge characteristic test repetition index n and the discharge current management index j, it is not particularly necessary because the discharge tester only needs to store the discharge test. However, it is convenient when a discharge characteristic test is automatically performed by a computer.

Steps S23 to 25: The first discharge current I _j illustrated in FIG. 4 and below is continuously discharged for each first discharge time t _j , and the terminal voltages V1 to V4 of the known storage battery at that time are obtained. taking measurement.
In the present embodiment, as illustrated in FIG. 4, the discharge voltage is continuously measured with four first discharge currents I1 to I4 (j = 1 to 4), and the terminal voltages V1 to V4 of the storage battery are measured. To do. In the present embodiment, the maximum discharge current management index j _max is 4.
FIG. 4 is a graph illustrating the method of the first discharge characteristic test of the present invention, in which the horizontal axis indicates the passage of time (or discharge time), and the vertical axis indicates the value and change of the first discharge current. is there.

For example, using a battery capacity of the storage battery during charging 20Ah as a sample (sample), in the case of performing the first discharge test for battery in a fully charged state, the illustration of the first discharge current I1~I4 the discharge time t _j Shown in Table 1 below.
However, although the first discharge current and the first discharge time are set, the terminal voltages V1 to V4 are measured values and not set values.

(Table 1)
Index j Discharge current Discharge time Terminal voltage j = 1 I1 = 5A t1 = T11 (seconds) V1
j = 2 I1 = 10A t2 = T12 (seconds) V2
j = 3 I1 = 20A t3 = T12 (seconds) V3
j = 4 I1 = 30A t4 = T12 (seconds) V4

In this example, for simplification, t2 = t3 = t4 = T12 (seconds).
Thus, for example, the discharge test is continuously performed with four types of first discharge currents I1 to I4, and the terminal voltages V1 to V4 at that time are measured.
The value of the first discharge current I _j is changed in order to measure the terminal voltage in various states in a certain remaining capacity or SOC, and further, by performing this discharge process, the initial state is fully charged. To reduce the remaining capacity or SOC of the storage battery for the second time, for example to 70%, for the third time, for example to 40%, for the fourth time, for example to reduce to 10% It is set.
As described above, since the value of the first discharge current is relatively large, the first discharge times t1 to t4 do not need to be long, and may be any time as long as the terminal voltage is stable and accurate measurement is possible.

Step S26: performing constant second discharge current (constant current discharge discharge current) I _d at a second discharge time (constant current discharging discharge period) t _d by constant current discharge.
This constant current discharge treatment is for adjusting the remaining capacity or SOC for the next discharge characteristic test.
For example, the second discharge current I _d = 4A, which is lower than the first discharge current I1 = 5A. Also, when compared to the second discharge time t _d, the first discharge time t1 to t4 (T11, T12) is short. For example, t _d = 30 minutes, T11 = 1 minute, and T12 = 30 seconds.
As described above, the remaining capacity or the SOC is adjusted at the second discharge time t _d longer than the first discharge time at the second discharge current I _d lower than the first discharge current I _j .

Step S27: As a result of the discharge, it is determined whether or not the actually measured terminal voltage V has dropped to a specified minimum voltage V ₀ , for example, 10.5V. The specified minimum voltage V ₀ is a voltage indicating a limit not to use the storage battery below this voltage, in other words, below the remaining capacity or SOC at that time.

In step S23, S26 according to 1st discharge of the storage battery in a fully charged state, usually, the actually measured terminal voltage V is not decreased to a specified minimum voltage V _0. In that case, the discharge characteristic test repetition index n is updated (n = n + 1), and the operation from step S22 is repeated again.

When the discharge characteristic test is performed a plurality of times, that is, when the remaining capacity or the SOC decreases from, for example, about 70%, about 40%, or about 10% from the fully charged state, for example, when the determination is made in step S27, the measured terminal The voltage V drops below the specified minimum voltage V ₀ . In that case, the above-described discharge test is terminated.

Even if the discharge characteristic test repetition number index n reaches the maximum number n _max or more, the discharge described above as an abnormal state also occurs when the measured terminal voltage V at the time of determination in step S27 does not drop below the specified minimum voltage V _0. End the test.

  For example, the discharge capacity D11 when the discharge current I1 = 5A is continuously discharged for T11 seconds, the discharge currents I2 = 10A, I3 = 20A, and I4 = 30A are each continuously discharged for T12 seconds is expressed by the following equation. The computer performs the following operations.

    D11 (Ah) = {5 (A) × T11 + (10 (A) +20 (A) +30 (A)) × T12} / 3600

The unit of the discharge capacity D11 is Ah, and in order to convert the discharge capacity D11 obtained by measuring time in seconds to a unit per hour, (1 hour = 60 seconds × 60 minutes =) is divided by 3600. .
As described above, for example, the first discharge current I1 = 5A and the first discharge time T11 seconds, and the first discharge currents I2 = 10A, I3 = 20A, and I4 = 30A are continuously discharged for the first discharge time T12 seconds. In this case, the number of times of measuring the voltage between terminals of the test storage battery (discharge characteristic test repetition number index) is n. Therefore, the total discharge capacity D12 discharged in these measurements is expressed by the following equation. The computer performs the following operations.

    D12 (Ah) = D11 × n

For example, the discharge capacity D2 when the second discharge time t _d = T21 hours with constant current discharge of the second discharge current I _d = 4A is expressed by the following equation. The computer performs the following operations.

  D21 (Ah) = 4 (A) × T21

When the constant current discharge is performed when the terminal voltage drops to the specified minimum voltage V ₀ , T22 hours, the total discharge capacity D22 when the constant current discharge is performed at the second discharge current I _d = 4A is When the number of times is m, it is expressed by the following formula. The computer performs the following operations.

  D22 (Ah) = D21 × m + 4 (A) × T22

  From the above, the discharge capacity obtained by adding the discharge capacity D12 and the discharge capacity D22, that is, the total discharge capacity D3 of the test storage battery is expressed by the following equation. The computer performs the following operations.

  D3 (Ah) = D12 + D22

For example, the first discharge current I1 = 5A is continuously discharged for the first discharge time T11 seconds, the first discharge currents I2 = 10A, I3 = 20A, and I4 = 30A are continuously discharged for the second discharge time T12 seconds, respectively. Prior to the process of actually measuring the inter-terminal voltage of the test storage battery, the previous 5A was continuously discharged for T11 seconds, 10A, 20A, and 30A each for T12 seconds, and between the terminals of the test storage battery at that time Assuming that the total of the discharge capacity in the process of actually measuring the voltage and the discharge capacity discharged from the test storage battery by the constant current discharge of the second discharge current I _d = 4A is D4, the first discharge current I1 = 5A is T11 seconds, The first discharge currents I2 = 10A, I3 = 20A, and I4 = 30A are each continuously discharged for T12 seconds, and the battery capacity in each process of measuring the voltage between the terminals of the test storage battery at that time is a plurality of values. Na It expressed as residual capacity D5, represented by the following formula. The computer performs the following operations.

  D5 (Ah) = D3-D4

The relationship between the inter-terminal voltages corresponding to, for example, the first discharge current I1 = 5A, the first discharge current I2 = 10A, I3 = 20A, and I4 = 30A measured in the respective remaining capacities of the plurality of remaining capacities D5 is shown. 5 (A) to (D).
The graphs illustrated in FIGS. 5A to 5D are results obtained by computing the computer and approximating the relationship between the plotted discharge current value (horizontal axis) and the voltage between terminals (vertical axis) by the least square method. Each of the characteristic curves Ll to L4 can be expressed as a substantially straight line. Then, the slope of the approximate straight line from the characteristic curves Ll to L4 when the discharge current is used as a parameter is the first coefficient a _SOC.
And
When the percentage of the plurality of remaining capacities D5 with respect to the total discharge capacity D3 at this time is calculated, it is (D5 / D3) × 100%. This calculation is also performed by the computer.
In this case, as shown in Table 2, the percentages of the plurality of remaining capacities D5 are, for example, 100%, 70%, 40%, and 10%, and correspond to the characteristic lines L1 to L4.
From the graphs illustrated in FIGS. 5A to 5D, the slope in the linear expression using the discharge current as a parameter, that is, the first coefficient a _SOC can be obtained.
In Table 2, I is the first discharge current, and V _SOC is the terminal voltage V ₁₀₀ , V ₇₀ , V ₄₀ , V ₁₀ for each remaining capacity or each SOC.
Table 2 shows the relationship between the discharge current and the terminal voltage that put on each remaining capacity of the battery.

(Table 2)
Terminal voltage V _SOC 1st coefficient a _SOC 2nd coefficient b _SOC for total discharge capacity
Remaining capacity or SOC
100% V ₁₀₀ = a1 (= 0.02) x I + b1
70% V ₇₀ = a2 (= 0.03) x I + b2
40% V ₄₀ = a3 (= 0.04) x I + b3
10% V ₁₀ = a4 (= 0.05) x I + b4

From the above, it can be seen that the first coefficient a _SOC in relation _{1, V SOC = a SOC ×} I + b SOC was determined.
However, b1, b2, b3, and b4 corresponding to the second coefficient b _SOC (intercept) in the relational expression 1 are unknown numbers, and how to find them will be described below.

How to determine the second coefficient A storage battery that is the same as or similar to the storage battery used when determining the first coefficient a _SOC is used as a sample, and the storage battery is fully charged.
As illustrated in FIG. 6, for example, the constant discharge is performed at the second discharge current I _d = 4 A until the voltage between the terminals of the storage battery is reduced to a specified minimum voltage V ₀ , for example, 10.5 V. The discharge time is T31.
In this discharge test, the elapsed time (discharge time) and the terminal voltage V of the storage battery at that time are measured. An example in which the results are plotted is shown in FIG. In FIG. 7, the horizontal axis represents the discharge time, and the vertical axis represents the terminal voltage.

  The total discharge capacity D6 at this time is represented by the following formula, for example. The computer performs the following operations.

  D6 (Ah) = 4 (A) × T31

Any percentage of the remaining capacity D7 (D7 / D6) × 100 % of the storage battery relative to the total discharge capacity D6 at this time it is possible to easily calculate a current value at each percent as illustrated in FIG. 8 Ru can be obtained a relationship of terminal voltage. By applying this discharge current, inter-terminal voltage, and the obtained first coefficient to the respective linear expressions in Table 2 based on Expression 1, the second coefficient in each percentage (each remaining capacity or each SOC). b Determine the _SOC .
FIG. 8 shows the relationship between the remaining capacity of the storage battery and the terminal voltage illustrated in FIG. 7 obtained by the constant current discharge illustrated in FIG. 6. The horizontal axis indicates each remaining capacity of the storage battery, and the vertical axis indicates the storage battery. The terminal voltage is shown.

The relationship between the current and the terminal voltage when the remaining capacity matches the percentage (100%, 70%, 40%, 10%) of the plurality of remaining capacity with respect to the total discharge capacity when the first coefficient a _SOC is obtained 8 can be obtained from the second coefficient exemplified in Table 8, and an example of the obtained result is shown in Table 3.
Table 3 is an example of the second coefficient showing the relationship between the voltage and current between the terminals of the storage battery in each remaining capacity of the storage battery. The second coefficient b _SOC means the intercept of relational expression 1.

(Table 3)
Second coefficient b _AOC
b1 = 12.42
b2 = 12.18
b3 = 11.74
b4 = 11.3

From the above examples of actual relational expressions , exemplary relational expression 1 is defined below.

(Table 4)
Terminal voltage vs. total discharge capacity V _SOC a _SOC b _SOC
Remaining capacity or SOC
100% V ₁₀₀ = 0.02 × I + 12.42
70% V ₇₀ = 0.03 × I + 12.18
40% V ₄₀ = 0.04 × I + 11.74
10% V ₁₀ = 0.05 × I + 11.3

The relational expression illustrated in Table 4 is a relational expression for 100% (full charge state), 70%, 40%, and 10%, which are the remaining capacity or SOC of a typical storage battery.
This relational expression can be expressed as a curve illustrated in FIG.

Hereinafter, description will be made with reference to step S2 of FIG. 1, FIG. 9B, and the calculation means 10, the ammeter 8 and the voltmeter 7 incorporating the computer and the memory illustrated in FIG.
Step S2a in FIG. 1: The above relational expression is converted into a data table and stored in, for example, the memory unit in the arithmetic means 10 incorporating the computer illustrated in FIG.

FIG. 1, step S2b: At a certain timing, the ammeter 8 measures the current I flowing through the battery 3, and the voltmeter 7 measures the terminal voltage V of the battery 3.
The measured current I is substituted into the relational expression for each remaining capacity or each SOC, and the voltage V _{SOC = 10%} , V _{SOC = 40%} , V _{SOC =} at each remaining capacity or each SOC at the time of the measured current I _70%
V _{SOC = 100%} is obtained. The voltage thus obtained is referred to as a calculation terminal voltage V _SOC in each remaining capacity.

FIG. 1, Step S2c: The terminal voltage V measured by the voltmeter 7 and the calculated terminal voltages V _{SOC = 10%} , V _{SOC = 40%} , V _{SOC = 70%} , V _{SOC = 100%} obtained by the above calculation. In comparison, it is determined in which range the terminal voltage V is located with respect to the calculation terminal voltage.
In the example illustrated in FIG. 9B, as a result of comparison, it is understood that the measured terminal voltage V is located between the terminal voltage V _{SOC = 40%} and V _{SOC = 70%} obtained by calculation. (V _{SOC = 40%} <V <V _{SOC = 70%} ). From this, it can be seen that the remaining capacity or SOC of the secondary storage battery at a certain timing is more (higher) than 40% and lower (lower) than the remaining capacity or SOC at full charge.
Furthermore, the remaining capacity or SOC of the secondary storage battery at a certain timing can be obtained by linear interpolation based on the following equation.

SOC _V = 0.4
+ (0.7 −0.4) × ((V _{SOC = 70%} −V) / (V _{SOC = 70%} −V _{SOC = 40%} )

The processing in step S2c described above is preferably performed in the arithmetic means 10 incorporating the CPU of the computer illustrated in FIG.
As described above, when the calculation means 10 is used, the data illustrated in FIG. 9A is discharged to the terminal voltage V _SOC and the discharge with respect to the remaining capacity or SOC within the range of 10 to 100% as illustrated in FIG. 9B. The relationship with the current can be easily obtained.
In other words, with respect to the remaining capacity or SOC = 1 to 100% of the lead storage battery 3, the remaining capacity or SOC can be obtained from the measured discharge current, terminal voltage, and operation terminal voltage V _SOC .

  In implementing this embodiment, no specially complicated components are required, and the signal processing in the computing means 10 is not particularly complicated, so that it can be put into practical use easily and at low cost.

Second Embodiment As a second embodiment of the present invention, the second embodiment of the present invention is mounted on a vehicle having a so-called idling stop function that stops an internal combustion engine (engine) during a temporary stop at a traffic jam or an intersection while the vehicle is running. A method and apparatus for determining the remaining capacity and deterioration state of the secondary storage battery, and a method and apparatus for performing idling stop processing based on the determination result of the remaining capacity and deterioration state of the secondary storage battery will be described.

FIG. 10 is a configuration diagram of an apparatus for determining the remaining capacity and / or deterioration state of the secondary storage battery according to the second embodiment of the present invention (hereinafter, remaining capacity / deterioration state determination apparatus).
In a vehicle, for example, an ordinary passenger car, a starter 1, a generator (alternator) 2, a secondary storage battery 3, an electric equipment 4, an engine 5, and an engine control unit 6 are connected via a bus 9. Is installed.
As the secondary storage battery 3, a case where a lead storage battery is used will be described.
The electric equipment 4 is a general term for things mounted on a vehicle that operates by electricity such as various lights (lamps) such as an illumination lamp, a direction indicator lamp, a hazard lamp, a mirror drive motor, an operation panel, and an air conditioner.

The remaining capacity / degradation state determination device illustrated in FIG. 10 includes a voltmeter 7 that measures the terminal voltage of the lead storage battery 3, an ammeter 8 that measures the discharge current flowing through the secondary storage battery 3, and the remaining capacity of the lead storage battery 3. -It has the calculating means 10 which calculates a degradation state, and the display means 16 which displays the result of the calculating means 10.
The remaining capacity / degradation state determination apparatus illustrated in FIG. 10 can include a control unit (not shown) that performs a vehicle drive control process according to the result of the calculation unit 10. The engine control unit 6 also constitutes a part of the control means, but is illustrated here as a dedicated control means for performing various controls of the engine 5 based on the result of the calculation means 10.
Furthermore, an idling stop (IS) processing unit 14 that performs an idling stop (IS) process according to the result of the calculation unit 10 can be included. In this case, the remaining capacity / deterioration state determination device has an idling stop processing function. This is a device for determining the remaining capacity and / or deterioration state of the secondary storage battery.

The starter 1 provides electric power for operating the engine 5 by power supply from the lead storage battery 3 when the vehicle is started.
The alternator 2 is activated to generate electric power when the vehicle is started and the engine 5 is rotated. In addition to supplying power to the electric equipment 4 by the power generation of the alternator 2, the lead storage battery 3 is charged.

The calculation means 10 has a calculation unit such as a microcomputer and a memory unit, and the remaining capacity of 100%, 70%, 40%, 10% exemplified in Table 4 and FIG. Alternatively, the first coefficient, the second coefficient, and the terminal voltage V _SOC used in the relational expression between the discharge current and the terminal voltage V _SOC for the _SOC are stored as a data table.

The ammeter 8 measures the charge / discharge current flowing through the lead storage battery 3. In addition, when the reading of the ammeter 8 is negative, it indicates that the discharge current flows from the lead storage battery 3 to the electrical equipment 4 and the like. When the reading is positive, the charging current flows from the generator (alternator) 2 to the lead storage battery 3. It shows that.
When the discharge current detected by the ammeter 8 is input to the calculation unit of the calculation unit 10, usually the CPU 10 of the microcomputer, and the relational expression 1 is calculated using the first coefficient and the second coefficient stored in the memory unit, The calculation terminal voltage V _SOC can be calculated.

Then, the CPU of the calculation means 10 determines the remaining capacity or SOC of the lead storage battery 3 by the method described above as the first embodiment from the actually measured current, the terminal voltage, and the calculation terminal voltage V _SOC .

The CPU of the calculation means 10 can output the determined remaining capacity or SOC via the display means 16.
The display means 16 is a device that displays the result of the calculation means 10 on a vehicle driver or the like, and is, for example, a liquid crystal display provided on the dashboard portion of the vehicle, It can also be used.
For example, when the driver or mechanic wants to know the current remaining capacity or SOC of the lead storage battery 3, the remaining capacity stored in the memory unit of the computing unit 10 by accessing the computing unit 10 via the operation unit (not shown). Alternatively, the remaining capacity or the SOC can be confirmed by displaying the SOC on, for example, the display unit 16 or the display unit of the operation panel of the vehicle. As a result, the lead storage battery 3 can be replaced at an appropriate timing. Alternatively, when some failure occurs in the vehicle, the remaining capacity or SOC calculated by the calculation means 10 can be checked to diagnose whether or not the cause of the failure occurred because the SOH of the lead storage battery 3 is low.

Also preferably, the CPU of the computing means 10 outputs the determined remaining capacity or SOC to the idling stop (IS) processing means 14.
The IS processing means 14 can supply the remaining capacity or SOC of the lead storage battery 3 determined by the CPU of the arithmetic means 10 to the minimum power supply portion of the electrical equipment 4 during idling stop, and after idling stop for a predetermined time, the starter 1 Is restarted, and it is determined whether or not the electric power sufficient for normal operation of the vehicle remains in the lead storage battery 3, and when there is a margin, idling stop processing is performed.

As described above, according to the second embodiment of the present invention, the remaining capacity or the SOC of the in-vehicle lead storage battery is accurately determined by applying the highly accurate relational expression obtained by the first embodiment. be able to.
As a result, the remaining life of the lead storage battery 3 can be predicted, and the lead storage battery 3 can be replaced at an appropriate timing.
Further, it is possible to appropriately perform idling stop processing.

  It should be noted that when implementing this embodiment, no specially complicated components are required, and signal processing is not complicated, so that it can be put into practical use easily and at low cost.

The embodiment described above is an exemplification, and the application of the present invention is not limited to the embodiment described with reference to the drawings and the above description, and those skilled in the art based on the contents described in the specification and the drawings. Anything that can be recalled should be considered as belonging to the present invention.
For example, in the above embodiment, the case where a lead storage battery is used as the secondary storage battery has been described. However, the present invention is not limited to the lead storage battery, and can be applied to various rechargeable secondary storage batteries. it can.

FIG. 1 is a diagram illustrating processing steps as a basic form of the present invention. FIG. 2 is a process diagram illustrating how to obtain the first coefficient a _SOC and the second coefficient b _SOC in Equation 1. FIG. 3 is a process diagram illustrating how to obtain the first coefficient a _SOC . FIG. 4 is a graph illustrating the method of the first discharge characteristic test of the present invention. 5 (A) to 5 (D) are graphs showing the relationship between the discharge current and the terminal voltage for the remaining capacity or SOC of a known lead storage battery. FIG. 6 is a graph illustrating a process of performing a constant current discharge. FIG. 7 is a graph showing an example in which the elapsed time (discharge time) in the discharge test and the terminal voltage V of the storage battery at that time are plotted. FIG. 8 is a graph showing the relationship between the remaining capacity of the storage battery and the terminal voltage obtained by the constant current discharge illustrated in FIG. FIG. 9A is an example of the contents of the relational expression obtained in the first embodiment of the present invention, and FIG. 9B is a graph showing a method for obtaining the remaining capacity or SOC from the relational expression. FIG. 10 is a configuration diagram of an apparatus for determining the remaining capacity or SOC (hereinafter, remaining capacity / SOC determination apparatus) of the secondary storage battery according to the second embodiment of the present invention.

Explanation of symbols

1. Starter, 2. Alternator,
3 .... Secondary battery (lead battery) 4 .... Electric equipment 5 .... Engine,
6 .... Engine control unit, 7 .... Voltmeter, 8 .... Ammeter,
10 .... Calculating means 14 .... Idling stop (IS) processing means 16 .... Display means

Claims (13)

V _SOC = a _SOC × I _j + b _SOC used to determine the remaining capacity or SOC of the secondary storage battery (V _SOC is a voltage between calculation terminals, I _j obtained by calculation in each remaining capacity or each SOC of the secondary storage battery. Is a discharge current, a _SOC is a first coefficient that means a slope, and b _SOC is a second coefficient that means an intercept). A method for obtaining a coefficient,
As a first discharge characteristic test, in each remaining capacity or each SOC of the secondary storage battery, a first discharge in which the terminal voltage of the secondary storage battery is stabilized by a plurality of first discharge currents (I _j ) whose values are sequentially decreased. discharge during the time, a first step of measuring the inter-terminal voltage of the secondary battery in the first discharge characteristic test,
Wherein from each remaining capacity or the plurality of sets of inter-terminal voltage obtained by the measurement at each SOC and the each first discharge current, in each of the remaining capacity or the respective SOC, the first coefficient (a _SOC) a calculated Mel second step of,
A second discharge characteristic test, a third step of the secondary battery from the fully charged state and a constant current discharge at a second discharge current, measures the terminal voltage of the secondary battery in the second discharge characteristic test,
Introducing a terminal voltage of each remaining capacity or the SOC measured during the elapsed time obtained by the second discharge characteristic test, the first coefficient determined the a discharge current to the linear expression, the remaining capacity Or a fourth step of _obtaining the second coefficient (b _SOC ) in each SOC ;
Having
A method of obtaining a first coefficient and a second coefficient used for calculating a voltage between calculation terminals used for determining a remaining capacity or SOC of a secondary storage battery . In the first discharge characteristic test in the first step, in order to perform the first discharge characteristic test in the next remaining capacity or the next SOC, after the current first discharge characteristic test, a discharge is performed at a predetermined discharge current. Performing discharge for adjustment to adjust to the value of the next remaining capacity or the next SOC;
Method person of claim 1. At the time of full charge of the secondary storage battery in the third step , each of the fixed first discharge currents (I1 to I4) is discharged only during the first discharge time (T11, T12), and the terminals at this time A first measuring step for measuring an inter-voltage;
A first adjustment step of adjusting discharge capacity by continuing constant current discharge at a constant second discharge current in the third step for an arbitrary time;
A repetition step of repeating the first measuring step and the first adjusting step, until the terminal voltage of the secondary battery in the first adjustment step is defined minimum voltage (V ₀₎ or less,
When the terminal voltage of the secondary battery is below the prescribed minimum voltage (V _0), at the said constant multiple of the first current is the product of the sum of the first discharge period of time the first measuring step The discharge capacity to be discharged, the first discharge capacity defined by the product of the number (n) of performing the first measurement process in the repetition process, and the terminal voltage of the secondary storage battery in the first adjustment process . the prescribed minimum voltage (V ₀₎ until be performed repeatedly until the drop, the second defined by the product of the total time and the constant second discharge current of time constant current discharging at the constant second discharge current and discharge capacity, a step to define the total discharge capacity (Q1) of the first discharge capacity and the second discharge capacity and the secondary battery of the third discharge capacity which is the sum of,
And before carrying out the said respective first measuring step, the total amount of discharge capacity is discharged by the discharge capacity by the second discharging current and the first measurement step, the total discharge capacity of the secondary storage battery (Q1) for each remaining capacity obtained by subtracting the determined Mel first coefficient calculating step said first coefficient (a _SOC) and a plurality of sets of inter-terminal voltage the each first discharge current obtained by the measurement,
Percentage (An) of each remaining capacity of the secondary storage battery when determining the first coefficient (a _SOC ) and each remaining capacity of the secondary storage battery and the secondary when determining the first coefficient (a _SOC ) and I asked Mel process from the total discharge capacity of the storage battery (Q1),
During full charge of the secondary storage battery or another secondary storage battery having the same capacity and charge / discharge characteristics as the secondary storage battery , a predetermined third current (Id3) continues for an arbitrary discharge time between predetermined terminals. A second measurement step of discharging until the voltage drops, and measuring the voltage between the terminals at this time;
A fourth discharge capacity is defined by the product of said third current (Id3) and the discharge time (T3) defined as the total discharge capacity (Q2), the terminal and the percentage (Bn) of the total discharge capacity (Q2) The relationship between the inter-voltage and the result, the obtained first coefficient and discharge current, and the first discharge current are introduced into the primary equation to obtain the second coefficient for each remaining capacity or each SOC. A second coefficient calculating step for _obtaining (b _SOC ),
Method person according to claim 1 or 2. The results indicating the relationship between the terminal voltage and the percentage (Bn) of the total discharge capacity (Q2), the inter-terminal voltage when the percentage of claim 1 (An) matching percentage and (Bn) (Vn And determining the discharge current (Id3),
Method who claim 3. From the first coefficient indicating the slope of the primary expression, the voltage (Vn) between the terminals at the time of the percentage (Bn), and the discharge current (Id3), each residual capacity or each SOC of the primary expression Determining the second coefficient (b _SOC ) meaning an intercept ;
Method who claim 4. The first coefficient (a _SOC ) and the second coefficient (b _SOC ) in each remaining capacity or each SOC obtained by the method according to claim 1 are assigned to each remaining capacity or each SOC. Corresponding to a table ,
Discharge current and the terminal of the first coefficient (a _SOC) and the second coefficient (b _SOC) was determined with the same charge and discharge characteristics and the same capacity as the secondary battery, the secondary battery to be determined residual capacity or SOC Measure the voltage between
Introducing the measured discharge current, the _tabulated first coefficient (a _SOC ), and the second coefficient (b _SOC ) into the relational expression to calculate the inter- operation terminal voltage (V _SOC ),
Comparing the measured inter- terminal voltage and the calculated inter- operating terminal voltage (V _SOC ) to determine the remaining capacity or SOC of the secondary storage battery to determine the remaining capacity or SOC;
A method for determining the remaining capacity of a secondary storage battery. When the measured inter- terminal voltage is located between two adjacent ones of the arithmetic inter- terminal voltages, the corresponding inter- terminal voltage is calculated by interpolation,
Determining the remaining capacity or SOC of the secondary storage battery to determine the remaining capacity or SOC based on the calculated inter- terminal voltage;
A method for determining the remaining capacity of the secondary storage battery according to claim 6 . The method according to any of claims 1 to 5, a linear expression that associates the discharge current in each remaining capacity or the SOC of the secondary battery (I _j) and calculating the inter-terminal voltage at that time (V _SOC), V _{SOC = a SOC × I j + b} SOC ( However, V _SOC arithmetic terminal voltage, I _j is the discharge current, a _SOC the first coefficient, b _SOC to mean slope is second coefficient means intercept) in Obtaining a first coefficient and a second coefficient ;
When a secondary storage battery having the same capacity and the same charge / discharge characteristics as the secondary storage battery and whose remaining capacity or SOC is to be determined is mounted on a vehicle, between the terminals of the secondary storage battery whose remaining capacity or SOC should be determined Measuring voltage and discharge current;
Introducing the measured discharge current and the first coefficient and the second coefficient into the linear equation to determine the inter- operation terminal voltage (V _SOC );
Comparing the measured inter- terminal voltage and the calculated inter- operation terminal voltage to determine the remaining capacity or SOC of the secondary storage battery to be determined the remaining capacity or SOC mounted on the vehicle,
A method for determining the remaining capacity of a secondary storage battery. In the step of obtaining the first coefficient and the second coefficient in the linear expression , the first coefficient (a _SOC ) and the second coefficient (b _SOC ) and the terminal voltage are tabulated in association with each remaining capacity or each SOC. ,
The secondary storage battery discharge current and the inter- terminal voltage for determining the remaining capacity or SOC are measured, and the measured discharge current, the first coefficient (a _SOC ) and the second coefficient ( b _SOC ) into the primary equation to calculate the voltage between the calculation terminals (V _SOC ),
Comparing and comparing the measured inter- terminal voltage and the calculated inter- terminal voltage (V _SOC ) to determine the remaining capacity or SOC of the secondary storage battery to determine the remaining capacity or SOC;
A method for determining the remaining capacity of the secondary storage battery according to claim 8. When the measured inter- terminal voltage is located between two adjacent ones of the arithmetic inter- terminal voltages, the corresponding inter- terminal voltage is calculated by interpolation,
Determining a remaining capacity or SOC of the secondary storage battery based on the calculated inter- terminal voltage;
A method for determining the remaining capacity of the secondary storage battery according to claim 9. The remaining capacity or SOC of the secondary storage battery for which the remaining capacity or SOC determined by the method for determining the remaining capacity of the secondary storage battery according to any one of claims 8 to 10 has stopped the vehicle from idling. After that, it is determined whether or not the remaining capacity or SOC can restart the vehicle.
A method for determining the remaining capacity of a secondary storage battery. Determined by the method of any of claims 1 to 5, the discharge current in each remaining capacity or the SOC of the secondary battery (I _j) and a linear equation relating the terminal voltage at that time (V _SOC), V _{SOC = a SOC × I j + b} SOC ( However, V _SOC arithmetic terminal voltage, I _j is the discharge current, a _SOC the first coefficient, b _SOC is a is a second coefficient) first coefficient and the second coefficient used for Memory means for storing each of the remaining capacity or each SOC in association with each other ,
When the front Symbol secondary storage battery or the remaining capacity or a secondary battery to be judged SOC having the same charge-discharge characteristics and the same capacity as the secondary蓄 battery is mounted on the vehicle, is mounted on the vehicle It means for measuring the inter-terminal voltage of the secondary battery and the discharge current are,
A discharge current in said measurement, said the memory means are stored in association with each remaining capacity or the SOC first coefficient and the introduction to the operation terminal voltage of the second coefficient to the linear expression (V _SOC First calculating means for obtaining
A determination means for comparing the measured inter- terminal voltage and the calculated inter- terminal voltage to determine the remaining capacity or SOC of the secondary storage battery that should determine the remaining capacity or SOC mounted on the vehicle; A device that determines the remaining capacity of the secondary storage battery. The remaining capacity or SOC of the secondary storage battery determined by the device for determining the remaining capacity of the secondary storage battery according to claim 12 can restart the vehicle after idling stop of the vehicle. Having means for determining whether or not
A vehicle having an idling stop function.

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