JP2002168929A - Method and device for measuring genuine resistance of battery for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a genuine resistance of a battery to be measured even under use of a vehicle. SOLUTION: A terminal voltage and a discharge current of the battery mounted on the vehicle are measured periodically by a voltage.current measuring means 23a-1 when the discharge current flows in a load mounted on the vehicle. A variation calculating means 23a-2 finds variations per unit time of the terminal voltage and the discharge current based on the terminal voltage and the discharge current obtained by the voltage.current measuring means when the discharge current increasing suddenly upto a prescribed value or more flows during a prescribed period. A dividing means 23a-3 divides the variation of the terminal voltage found by the variation calculating means by the variation of the discharge current. A value found by the dividing means is measured as the genuine resistance of the battery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring the pure resistance of a battery mounted on a vehicle for supplying power to a load mounted on the vehicle.

[0002]

2. Description of the Related Art Generally, when a current is discharged from a battery, a terminal voltage of the battery drops. The voltage drop is due to the internal impedance (combined resistance) of the battery, but the IR loss (pure resistance, that is, the voltage drop due to ohmic resistance) due to the structure of the battery and the polarization resistance due to the chemical reaction. It can be divided into voltage drops due to components (activation polarization, concentration polarization). When the voltage-current (VI) characteristic is obtained, the voltage drop due to IR loss does not change if the state of the battery is the same, but the voltage drop due to the polarization resistance component is the magnitude of the current and the current is discharged. It changes with time. Therefore, it can be seen that inferring various states of the battery from the VI characteristics including the polarization resistance component results in an inaccurate estimation result. Therefore, a technique for measuring only the pure resistance separated from the polarization resistance component is necessary. It is said.

A battery can be repeatedly used within its charge capacity by charging the battery so as to cover a discharge current. However, if an unexpected situation such as an overdischarge or a shortage of an electrolyte occurs, the battery may be used. Of course, even if these situations do not occur, if the battery is used for a long time and aging occurs, the dischargeable capacity, which is the amount of power that can be supplied to the load by the discharge, rapidly decreases. For this reason, in a state where the dischargeable capacity is reduced due to aging, even if a discharge exceeding the charge occurs for a short period of time, the starter motor may be started after the engine is stopped and the engine may not be restarted. Absent.

Incidentally, when a new battery is compared with a battery that has undergone aging, it is known that a battery that has undergone aging has a higher net resistance than a new battery. Therefore, it has been considered to measure the pure resistance of the battery as a guide for battery replacement at the time of periodic inspection of the vehicle or the like. This is by knowing the net resistance
This is because the degree of deterioration can be determined in consideration of the ratio between the pure resistance and the polarization resistance component. Also, knowing the pure resistance can be used to estimate the open circuit voltage of the battery.

Conventionally, in a measuring instrument generally used for measuring the pure resistance of a battery, when the battery is in a static state, that is, when the battery is charged or discharged, a voltage rise or a voltage drop such as polarization occurs in the electrolyte. The battery's net resistance is measured when it is in equilibrium, where it has not occurred.

[0006] As an example, the battery has a frequency of 1 kHz to 1 kHz.
A method of obtaining a pure resistance from a relationship between a voltage and a current that changes within a certain period of time, for example, about 1 μs, in a situation where charging and discharging are repeated by applying an alternating current having a frequency of about 00 kHz and neither polarization of charging nor discharging is accumulated. There is. This is because, as shown in FIG. 8, a phenomenon in which the voltage rapidly recovers after the discharge is stopped, and then recovers slowly thereafter, and a certain time ΔΔ
It is considered that the rapid voltage recovery within t is caused only by the component due to the pure resistance R, and the subsequent gradual change is caused by the components (capacitance and inductance components) other than the pure resistance, including the polarization.
The purpose of the present invention is to measure a change in voltage and current within a short time of each application cycle of an alternating current having a frequency of about 100 kHz to measure a pure resistance.

[0007]

However, when a battery mounted on a vehicle is used as a target, a static state exists only in a limited case, and is applicable when the vehicle is in use. Can not.

Further, in the method of the above-described example, since an arbitrary alternating current cannot be applied to the battery during operation of the vehicle, there is a reality that the method cannot be applied to measure the pure resistance of the battery during use of the vehicle.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method and an apparatus for measuring a battery pure resistance for a vehicle, which can measure the pure resistance of the battery even when the vehicle is in use.

[0010]

In order to achieve the above object, the present invention as defined in claims 1 to 3 provides a method for measuring a battery pure resistance for a vehicle.
Regarding each of the vehicle battery pure resistance measuring devices, the magnitude of the polarization finally generated by the discharge depends on the magnitude of the current, but the generation requires time, and the discharge current is reduced. In the case where the discharge current is abrupt, the discharge current does not catch up with the increase in the current, and even when the discharge current reaches a peak, the amount of generation is small, and attention is paid to this fact.

[0011] The present invention has been made to solve the above problems.
The described invention is a vehicle battery pure resistance measuring method for measuring a pure resistance of a battery mounted on a vehicle to supply power to a load mounted on the vehicle, wherein the discharge current flows through the load. Obtained by periodically measuring the terminal voltage and discharge current of the battery, based on the terminal voltage and discharge current obtained by the measurement when the discharge current that suddenly increases to a predetermined value or more flows for a predetermined period, The amount of change per unit time between the terminal voltage and the discharge current is obtained, and the value obtained by dividing the obtained amount of change in the terminal voltage by the amount of change in the discharge current is measured as the pure resistance of the battery. The present invention relates to a method of measuring a vehicle battery net resistance.

According to the above-described procedure, first, the terminal voltage and the discharge current of the battery mounted on the vehicle when the discharge current flows to the load mounted on the vehicle are periodically measured. Get it. Next, an amount of change per unit time between the terminal voltage and the discharge current is determined based on the terminal voltage and the discharge current when the discharge current that suddenly increases beyond a predetermined value flows during a predetermined period. Then, a value obtained by dividing the obtained change amount of the terminal voltage by the change amount of the discharge current is measured as the pure resistance of the battery.

[0013] Based on the terminal voltage and the discharge current when a discharge current that suddenly increases beyond a predetermined value flows for a predetermined period,
Since the amount of change per unit time between the terminal voltage and the discharge current is obtained, the polarization generated by the discharge current increased per unit time is very small, and the amount of change in the terminal voltage, that is, the voltage drop, is a polarization resistance component. Occupies a very small percentage and can be considered to be substantially due to pure resistance,
Therefore, the value obtained by dividing the amount of change in the terminal voltage by the amount of change in the discharge current can represent the pure resistance of the battery.

According to a second aspect of the present invention, in the method for measuring a battery pure resistance according to the first aspect, when the amount of change between the terminal voltage and the discharge current per unit time is obtained, the discharge current is set to a predetermined period. The present invention relates to a method of measuring a battery pure resistance for a vehicle, wherein it is detected that the value increases by a predetermined value or more.

According to the second aspect of the present invention, when determining the amount of change per unit time between the terminal voltage and the discharge current, it is detected that the discharge current increases by a predetermined value or more in a predetermined period. When the discharge current does not increase by a predetermined value or more during a predetermined period, the amount of change per unit time is not calculated, so that the accuracy of the measured pure resistance can always be within a predetermined range.

The third aspect of the present invention is the first or second aspect.
In the method for measuring a battery pure resistance for a vehicle according to the present invention, in detecting that the discharge current increases by a predetermined value or more in a predetermined period, at least the latest measured terminal voltage and discharge current of the battery are updated. Collected, stored, and stored for a predetermined period, and the discharge current has increased by a predetermined value or more in a predetermined period based on the stored terminal voltage and discharge current for the latest predetermined period. The method according to claim 1, further comprising the step of: determining the amount of change per unit time based on the terminal voltage and the discharge current within the predetermined period when the detection is performed.

According to the above-mentioned procedure, the terminal voltage and the discharge current of the battery measured periodically are collected, stored and stored for at least the latest predetermined period.
Based on the stored terminal voltage and discharge current for the latest predetermined period, based on the terminal voltage and the discharge current within the predetermined period, when detecting that the discharge current has increased by a predetermined value or more in the predetermined period, Since the amount of change per unit time is determined, processing for determining the pure resistance can be performed at any convenient time.

Claim 4 has been made to solve the above problem.
As described in the basic configuration diagram of FIG. 1, the described invention is a vehicle battery pure resistance measuring device that measures the pure resistance of a battery mounted on a vehicle to supply power to a load mounted on the vehicle. The voltage / current measuring means 23a-1 which periodically measures the terminal voltage and the discharge current of the battery when the discharge current flows through the load, and the discharge current that rapidly increases to a predetermined value or more for a predetermined period. A change amount calculating means 23a-2 for obtaining a change amount per unit time between the terminal voltage and the discharge current based on the terminal voltage and the discharge current obtained by the voltage / current measuring means when flowing; Dividing means 23a-3 for dividing the amount of change in the terminal voltage obtained by the amount calculating means by the amount of change in the discharge current, and measuring the value obtained by the dividing means as the pure resistance of the battery. It consists in the vehicle battery pure resistance measuring apparatus according to symptoms.

According to the fourth aspect of the present invention, the voltage / current measuring means 23a-1 determines the terminal voltage of the battery mounted on the vehicle when the discharge current flows through the load mounted on the vehicle. It is obtained by periodically measuring the discharge current. The change amount calculating unit 23a-2 calculates the terminal voltage and the discharge current based on the terminal voltage and the discharge current obtained by the voltage / current measuring unit when the discharge current that suddenly increases beyond a predetermined value flows for a predetermined period. And the amount of change per unit time. The dividing means 23a-3 divides the amount of change in the terminal voltage obtained by the amount of change calculating means by the amount of change in the discharge current. Then, the value obtained by the dividing means is measured as the pure resistance of the battery.

Based on a terminal voltage and a discharge current when a discharge current that suddenly increases over a predetermined value flows for a predetermined period,
Since the change amount calculating means 23a-2 obtains the change amount between the terminal voltage and the discharge current per unit time, the polarization generated by the discharge current increased per unit time is very small, and the change amount of the terminal voltage is small. That is, the ratio of the polarization resistance component to the voltage drop is extremely small, and can be regarded as substantially due to pure resistance.
The value obtained by dividing −3 by the amount of change in the terminal voltage by the amount of change in the discharge current can represent the pure resistance of the battery.

According to a fifth aspect of the present invention, in the vehicle battery pure resistance measuring apparatus according to the fourth aspect, the change amount calculating means determines the change amount of the terminal voltage and the discharge current per unit time. The present invention resides in a vehicle battery pure resistance measuring device having a current increase detecting means 23a-21 for detecting that the discharge current increases by a predetermined value or more in a predetermined period.

According to the configuration of the fifth aspect, the change amount calculating means 23a-2 determines the change amount of the terminal voltage and the discharge current per unit time. When it is detected that the current increases by a predetermined value or more in a predetermined period, and when the discharge current does not increase by a predetermined value or more in a predetermined period, the amount of change per unit time is not determined. The accuracy of the pure resistance can always be within a predetermined range.

According to a sixth aspect of the present invention, in the vehicle battery pure resistance measuring apparatus according to the fifth aspect, the change amount calculating means detects that the discharge current has increased by a predetermined value or more during a predetermined period. In addition, the storage device further includes a storage unit 23b that collects, stores, and stores at least the latest predetermined period of the terminal voltage and the discharge current of the battery that are periodically measured, and the latest stored in the storage unit. When the current increase detecting means detects that the discharge current has increased by a predetermined value or more in a predetermined period based on the terminal voltage and the discharge current for the predetermined period, the terminal voltage and the discharge in the predetermined period An amount of change per unit time is obtained from an electric current, and the present invention resides in a vehicle battery pure resistance measuring device.

According to the above-described configuration, the storage means 23b collects, stores and stores at least the latest predetermined period of the battery terminal voltage and the discharge current measured periodically. Based on the stored terminal voltage and discharge current for the latest predetermined period, the current increase detecting means 23
When a-21 detects that the discharge current has increased by a predetermined value or more during a predetermined period, the change amount calculating means 23a-2 calculates the change amount per unit time by the terminal voltage and the discharge current within the predetermined period. Since the calculation is performed, the processing for obtaining the pure resistance can be performed at any convenient time.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for measuring a vehicle pure resistance according to the present invention, together with a vehicle pure resistance measuring apparatus according to the present invention, will be described with reference to the drawings. To consider.

By the way, 12V car, 42V car, EV car, H
EV vehicles are equipped with loads requiring a large current, such as a starter motor, a motor generator, and a driving motor. These loads are supplied with electric power from a battery by turning on a switch, as shown in FIG. In addition, it has a current characteristic in which a rapidly increasing large current called a rush current flows at the beginning of the current flow and then rapidly decreases to a steady current.

When a load requiring a large current as described above is driven, a discharge current that monotonically increases beyond a predetermined value and monotonically decreases from a maximum value to a predetermined value or less flows by one discharge. 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, the discharge is started as shown in FIG. The current increase V with respect to the discharge current that suddenly increases beyond a predetermined value during a predetermined period toward the increasing direction
Two characteristics are obtained: a -I characteristic and a current decreasing VI characteristic for a discharging current in which the current reaches a maximum and then decreases in a decreasing direction. The difference between these two properties is analyzed below.

On the other hand, in the case of a current increase VI characteristic with respect to a discharge current that suddenly increases to a predetermined value of 200 A to 300 A or more within a predetermined period of several milliseconds, for example, the polarization resistance component at the start of discharge is used as a reference. Then, even if the discharge starts and the current increases, the rate of increase of the current is much faster than the generation rate of the polarization resistance component. Therefore, even if the discharge current reaches a peak, the polarization resistance corresponding to the magnitude of the current increases. No component is generated, and the ratio of the voltage drop due to the polarization resistance component to the voltage drop of the terminal voltage caused by the flow of the current is extremely small, and most of the ratio is due to the pure resistance component.

This becomes more apparent by analyzing the other current reduction VI characteristics. That is,
After the current reaches the maximum value, the polarization resistance component should disappear as the current decreases, but in fact, the polarization resistance component does not disappear in proportion to the decrease in the current, but rather It increases. This is because the generation rate of the polarization resistance component is low, and the polarization resistance component is still increasing even when the current is reduced. When the polarization resistance component corresponding to a certain current on the current decrease VI characteristic is generated, the voltage is increased. The voltage drop due to the polarization resistance component occupying the drop becomes the maximum ratio. Eventually, the polarization resistance component corresponding to the steady-state current will be resolved with a decrease in the current from the point where the polarization resistance component has been reduced. The voltage drop of the terminal voltage of the battery due to the component remains.

As described above, the terminal voltage of the battery when a discharge current that rapidly increases beyond a predetermined value flows for a predetermined period is a voltage reflecting the voltage drop caused by the discharge current flowing through the pure resistance of the battery. Occupying almost all of the voltage, and focusing on the fact that the voltage due to the polarization resistance component hardly appears, and measuring the pure resistance R of the battery using the current increase VI characteristic of the two VI characteristics described above. Is specifically described below with reference to FIGS.

The terminal voltage of the battery and the discharge current when the discharge current flows through a load requiring a large current, such as a starter motor, a motor generator, a traveling motor, etc., mounted on the vehicle are compared, for example, for 1 millisecond. The terminal voltage V and the discharge current are obtained as shown in the current increase VI characteristic of FIG. I
And ΔI and ΔI per unit time Δt.
Subsequently, a value obtained by dividing the obtained change amount ΔV of the terminal voltage V by the change amount ΔI of the discharge current I is measured as a pure resistance R.

In determining the amount of change between the terminal voltage and the discharge current per unit time, it is detected that the discharge current increases by a predetermined value or more during a predetermined period ΔT as shown in the current characteristics of FIG. This ensures that the accuracy of the pure resistance R measured by the value obtained by dividing the variation ΔV of the terminal voltage V by the variation ΔI of the discharge current I falls within a predetermined range. That is, in the case of a discharge current that increases by a predetermined value or more during a predetermined period ΔT, polarization is extremely small, and a voltage drop due to its resistance component is extremely small as negligible as compared with a pure resistance. The accuracy comes within a predetermined range. In addition, by detecting in advance that the discharge current increases by a predetermined value or more in a predetermined period, if this condition is not satisfied, the unit time Δt between the terminal voltage V and the discharge current I is determined.
It is not necessary to obtain the change amounts ΔV and ΔI per hit, and unnecessary processing can be eliminated.

When detecting that the discharge current has increased by a predetermined value or more during a predetermined period, the terminal voltage and the discharge current of the battery periodically measured are collected, stored, and stored at least for the latest predetermined period. Keep it. Then, based on the stored terminal voltage and discharge current for the latest predetermined period, when it is detected that the discharge current has increased by a predetermined value or more in the predetermined period, the stored latest Based on the terminal voltage and the discharge current for the predetermined period, the terminal voltage and the discharge current within the predetermined period determine the amount of change in the terminal voltage and the discharge current per unit time, so that any convenient Processing can be performed at the point.

Specifically, when a load requiring a large current, such as a starter motor, a motor generator, a traveling motor, or the like, is operated, the battery monotonically increases beyond a predetermined value, and increases from the maximum value to a predetermined value or less. , A discharge current that monotonously decreases flows. 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, stored, and collected for a predetermined period in a memory such as a rewritable storage device such as a RAM. . Using the set of the terminal voltage and the discharge current stored and stored in the memory and detecting, it is detected that the discharge current increases by a predetermined value or more in a predetermined period, and the discharge current increases by a predetermined value or more in a predetermined period. When it is detected that the terminal voltage and the discharge current are changed, the amount of change per unit time between the terminal voltage and the discharge current is obtained by using a set of the terminal voltage and the discharge current stored and stored in the memory. Then, the obtained amount of change in terminal voltage is divided by the amount of change in discharge current to measure the obtained value as the pure resistance of the battery.

A specific embodiment of an apparatus for performing the above-described method for measuring a battery pure resistance for a vehicle by enabling the above-described operation will be described below with reference to the drawings.

FIG. 2 is an explanatory view showing, in partial blocks, a schematic configuration of a vehicle battery pure resistance measuring apparatus according to an embodiment of the present invention to which the vehicle battery pure resistance measuring method of the present invention is applied. The vehicle battery resistance measuring apparatus according to the present embodiment, which is indicated by the reference numeral 1, 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 so 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 used as a cell motor for forcibly rotating the flywheel of the engine 3 when the engine 3 is started when a starter switch (not shown) is turned on. A large current flows in a short time.
When the engine 3 is started by the motor generator 5 by turning on the starter switch, the starter switch is turned off and the ignition switch and the accessory switch are turned on with the release of the operation of an ignition key (not shown). And the battery 13
The discharge current flowing from the battery shifts to a steady current.

Returning to the description of the configuration, the vehicle battery pure resistance measuring apparatus 1 of the present embodiment includes a motor generator 5 functioning as a motor for assisted driving or a cell motor.
A current sensor 15 for detecting a discharge current I of the battery 13 with respect to electric components and a charging current of the motor generator 5 functioning as a generator with respect to the battery 13.
And a voltage sensor 17 having an infinite resistance connected in parallel to the battery 13 and detecting a terminal voltage V of the battery 13.

Further, in the vehicle battery pure resistance measuring apparatus 1 of the present embodiment, the output of the current sensor 15 and the voltage sensor 17 is A / A in the interface circuit (hereinafter abbreviated as "I / F") 21. It further includes a microcomputer (hereinafter, abbreviated as “microcomputer”) 23 taken in after the D conversion.

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.
23c, the I / F 21 is connected, and
Starter switch (not shown), ignition switch, accessory switch, and motor generator 5 (not shown)
Switches and the like of other electrical components (loads) are further connected.

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

The current value and the voltage value output from the current sensor 15 and the voltage sensor 17 are sampled at high speed in a short cycle, and are taken in by the CPU 23a of the microcomputer 23 via the I / F 21 and taken in. The current value and the voltage value are stored and stored in a data area (corresponding to a storage means) of the RAM 23b from a value before a predetermined period to a latest value. The stored actual data is used to determine the voltage-current characteristics of the battery.

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 FIG.

When the microcomputer 23 is started up by receiving power supply from the battery 13 and the program is started, the CPU 23
First, a performs initial setting (step S1).

After the initial setting of step S1 is completed,
Next, the CPU 23a compares the A / D conversion value between the discharge current I of the battery 13 detected by the current sensor 15 and the terminal voltage V of the battery 13 detected by the
A real data collection process is performed in which the latest real data read through F21 is stored in the data area of the RAM 23b for a predetermined time, stored, and collected (step S2). The actual data collection process in step S2 is always performed continuously.

Subsequently, the actual data of the latest predetermined time between the discharge current I and the terminal voltage V collected in step S2 is analyzed, and it is determined whether or not the data is appropriate for application. That is, an analysis process is performed to analyze whether a discharge current that monotonically increases beyond a predetermined value flows from the battery (step S3).

As a result of the analysis in step S3, the voltage-
Those suitable for obtaining the current characteristics are collected, and it is determined whether or not the discharge current has increased by a predetermined value or more during a predetermined period ΔT (step S4). When the discharge current has increased by a predetermined value or more in a predetermined period (Y in step S4), that is, when it is detected that the discharge current has increased by a predetermined value or more in a predetermined period, the collection is performed within the predetermined period. Unit time Δ between the applied discharge current I and the terminal voltage V
The amounts of change ΔI and ΔV per t are obtained (step S
5).

After the change amounts ΔI and ΔV per unit time between the discharge current I and the terminal voltage V are determined in step S5, the change amount ΔV of the terminal voltage is then changed to the change amount ΔI of the discharge current.
Is measured as the pure resistance R of the battery (step S6). The measured pure resistance R is stored for use in various processes (step S7). If the determination in step S4 is N, step S2
Then, actual data for the latest predetermined time of the discharge current I and the terminal voltage V is collected, and as a result of the analysis in step S3, the above-described step S4 is performed until the determination in step S4 becomes Y.
Steps 2 to S4 are repeated.

Further, in the vehicle battery pure resistance measuring apparatus 1 of the present embodiment, step S2 in the flowchart is a process for the voltage / current measuring means 23a-1 in the claims, and step S4 is the current in the claims. The processing corresponds to the increase detecting means 23a-21, the step S5 corresponds to the change amount calculating means 23a-2 in the claims, and the step S6 corresponds to the dividing means 23a-3 in the claims. Has become.

Next, the operation (action) of the vehicle battery resistance measuring apparatus 1 of the present embodiment configured as described above will be described.

First, when an electric component (load) other than the motor generator 5 of the hybrid vehicle operates or the motor generator 5 operates so as to function as a motor, the load is started when the battery 13 starts discharging. During a predetermined period, a discharge current that monotonically increases to a predetermined value or more and monotonically decreases from the maximum value and reaches a steady state flows, and at least the terminal voltage of the battery and the discharge current at this time are periodically measured. Of course, the terminal voltage of the battery and the discharge current may be periodically measured at all times.

In the vehicle battery pure resistance measuring apparatus 1 of the present embodiment, the latest one periodically measured is stored, stored, and collected in the data area of the RAM 23b for a predetermined period. The latest actual data of the discharge current I and the terminal voltage V for the latest predetermined period is analyzed to determine whether or not the discharge current increased by a predetermined value or more from the battery during the predetermined period.

For this reason, until an appropriate one is collected,
Since the processing is not performed and the processing may be performed using actual data for a predetermined period collected in the past, the processing is not performed in synchronization with the periodic measurement of the terminal voltage and the discharge current. Also, high processing speed is not required.

Further, it is preferable that the predetermined period and the predetermined value are arbitrarily determined as long as the presence of the discharge current which has increased by a predetermined value or more during the predetermined period does not affect the required accuracy.

In the above-described example, the case where an electric component (load) other than the motor generator 5 is operated as the load is described. When a discharge current that exceeds a predetermined value within a predetermined period, such as a rush current, flows at the start of the operation, the voltage drop of the terminal voltage caused by the increase of the discharge current is caused by a pure resistance. The pure resistance is measured by dividing the amount of change in terminal voltage generated in this short time by the amount of change in discharge current.

In the above-described embodiment, the section of the discharge current which monotonously increases among the discharge currents flowing to the load is used for measuring the pure resistance. If a current change occurs, the monotonically decreasing discharge current may be used to measure the pure resistance.

In the above-described embodiment, the pure resistance of the battery is measured by using the discharge current flowing through the load. However, the charge current for charging the battery changes by a predetermined value or more within a predetermined period. In this case, the charging current can be used for measuring the pure resistance.

It should be noted that the term "pure resistance" used in the present specification does not mean a true ohmic resistance, but includes resistance components other than the ohmic resistance but includes only a negligible amount. , Which is very close to the true ohmic resistance.

[0062]

As described above, according to the first or fourth aspect of the present invention, the polarization generated by the discharge current increased per unit time is very small, and the amount of change in the terminal voltage, that is, the voltage drop is reduced. The ratio of the polarization resistance component is extremely small, and can be regarded as substantially due to the pure resistance. Therefore, the value obtained by dividing the change in the terminal voltage by the change in the discharge current represents the pure resistance of the battery. When using the battery in the normal state,
That is, it is possible to provide a vehicle battery pure resistance measuring method and device capable of measuring the battery pure resistance even during use of the vehicle.

According to the second or fifth aspect of the present invention, the accuracy of the measured pure resistance can always be within a predetermined range, so that the accuracy of the pure resistance measurement can be kept stable. It is possible to provide a method and apparatus for measuring a vehicle battery pure resistance that can be performed.

According to the third or sixth aspect of the present invention, it is possible to perform the processing for obtaining the pure resistance at any convenient time, so that unnecessary processing can be omitted.
It is possible to provide a vehicle battery pure resistance measuring method and device capable of measuring pure resistance without performing real-time high-speed processing.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of a vehicle battery pure resistance measuring device of the present invention.

FIG. 2 is an explanatory diagram showing, in partial blocks, a schematic configuration of a vehicle battery pure resistance measuring apparatus according to an embodiment of the present invention to which the vehicle battery pure resistance measuring method of the present invention is applied.

FIG. 3 is a graph showing current characteristics of a large current load.

FIG. 4 is a graph showing VI characteristics at the time of the current characteristics shown in FIG.

FIG. 5 is a graph showing current characteristics for explaining the present invention.

FIG. 6 is a graph showing a current increase VI characteristic for explaining the present invention.

FIG. 7 is a flowchart showing processing performed by the microcomputer in FIG. 2 according to a predetermined program for measuring pure resistance.

FIG. 8 is a graph for explaining a method of measuring a pure resistance of a conventional battery.

[Explanation of symbols]

 23a-1 Voltage / current measuring means (CPU) 23a-2 Change amount calculating means (CPU) 23a-21 Current increase detecting means (CPU) 23a-3 Dividing means (CPU) 23b Storage means (RAM)

Continued on the front page F term (reference) 2G016 CA03 CB06 CB12 CB21 CB23 CC01 CC03 CC04 CC12 CC16 CC24 CC27 CC28 CD03 5G003 AA01 CA01 CA11 EA09 FA06 GC05 5H030 AA06 AS08 FF42 FF44 FF52 5H115 PC06 PG04 PI13 PI16 PI29 PU01 PU23 Q QI04 QN03 TI02 TI05 TI06 TO30

Claims (7)

[Claims] 1. A method for measuring the net resistance of a battery mounted on a vehicle for supplying power to a load mounted on the vehicle, the method comprising the steps of: The terminal voltage and the discharge current of the battery are periodically measured, and based on the terminal voltage and the discharge current obtained by the measurement when the discharge current that suddenly increases to a predetermined value or more flows for a predetermined period, The amount of change per unit time between the terminal voltage and the discharge current is obtained, and the value obtained by dividing the obtained amount of change in the terminal voltage by the amount of change in the discharge current is measured as the pure resistance of the battery. Vehicle battery pure resistance measurement method. 2. The method for measuring a battery pure resistance of a vehicle according to claim 1, wherein the discharge current increases by a predetermined value or more in a predetermined period in obtaining a change amount per unit time between the terminal voltage and the discharge current. A method for measuring a vehicle battery pure resistance, characterized in that: 3. The method according to claim 2, wherein the terminal voltage of the battery is periodically measured when detecting that the discharge current increases by a predetermined value or more during a predetermined period. And the discharge current are collected and stored for at least the latest predetermined period, and stored based on the stored terminal voltage and discharge current for the latest predetermined period. A method for measuring a battery pure resistance for a vehicle, comprising: detecting a variation per unit time based on a terminal voltage and a discharge current within the predetermined period when detecting that there is an increase of not less than a predetermined value. 4. A vehicle battery pure resistance measuring device for measuring a pure resistance of a battery mounted on a vehicle for supplying electric power to a load mounted on the vehicle, wherein the battery pure resistance measuring device is configured such that when a discharge current flows through the load, A voltage / current measuring means obtained by periodically measuring a terminal voltage and a discharging current of a battery; and a voltage / current measuring means obtained when a discharging current that rapidly increases to a predetermined value or more flows for a predetermined period. A change amount calculating means for calculating a change amount per unit time between the terminal voltage and the discharge current based on the terminal voltage and the discharge current, and a change amount of the terminal current obtained by the change amount calculating means. And a dividing means for dividing by a quantity, wherein a value obtained by the dividing means is measured as a pure resistance of the battery. 5. The vehicle battery pure resistance measuring device according to claim 4, wherein the change amount calculating means calculates the change amount of the terminal voltage and the discharge current per unit time, and sets the discharge current to a predetermined period. A vehicle battery pure resistance measuring device, characterized by further comprising a current increase detecting means for detecting that the current increases by a predetermined value or more. 6. The vehicle battery pure resistance measuring device according to claim 5, wherein the change amount calculating means periodically measures when detecting that the discharge current has increased by a predetermined value or more in a predetermined period. And storing and storing the terminal voltage and the discharge current of the battery for at least the latest predetermined period, and storing the terminal voltage and the discharge current for the latest predetermined period stored in the storage unit. Based on the discharge current, when the current increase detection unit detects that the discharge current has increased by a predetermined value or more in a predetermined period, the change amount calculation unit detects the terminal voltage and the discharge current within the predetermined period. And calculating the amount of change per unit time. 7. A vehicle battery pure resistance measuring method for measuring a pure resistance of a battery mounted on a vehicle for supplying power to a load mounted on the vehicle, the method comprising: The terminal voltage and the charging current of the battery are obtained by periodically measuring the terminal voltage and the charging current.Based on the terminal voltage and the charging current obtained by the measurement when the charging current that rapidly increases to a predetermined value or more flows for a predetermined period, The amount of change per unit time between the terminal voltage and the charging current is obtained, and the value obtained by dividing the obtained amount of change in the terminal voltage by the amount of change in the charging current is measured as the pure resistance of the battery. Vehicle battery pure resistance measurement method.