JPH08146107A - Device for measuring internal resistance of storage battery - Google Patents

Abstract

PURPOSE: To improve measuring accuracy by providing another voltage measuring means for measuring the terminal voltage of another storage battery so as to measure a ripple component separately, and computing for eliminating the ripple component. CONSTITUTION: Before a predetermined current is made to flow in a first storage battery 31 by a current generating means 130, the terminal voltage of the first storage battery 31 and the terminal voltage of second storage battery 32 are separately measured by first voltage measuring means 120 and second voltage measuring means 121. When the predetermined current is made to flow in the first storage battery 31 by the current generating means 130, the terminal voltage of the first storage battery 31 and the terminal voltage of the second storage battery 32 are separately measured by the first voltage measuring means 120 and the second voltage measuring means 121. A computing/controlling means 140 conducts subtraction correction of the variation of the terminal voltage of the first storage battery 31 measured through the first voltage measuring means 120 by using the variation of the terminal voltage of the second storage battery 32 measured through the second voltage measuring means 121. The internal resistance of the first battery 31 is obtained thereby.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in measurement accuracy of a storage battery internal resistance measuring device for determining the internal resistance of a storage battery.

[0002]

2. Description of the Related Art FIG. 4 is a system configuration diagram showing an example of use of a storage battery. In this figure, 10 is a commercial power source, 20 is a rectifier, 30 is a storage battery, and 40 is a load. Rectifier 20
Has an input terminal and an output terminal, the commercial power supply 10 is connected to the input terminal, and the storage battery 30 and the load 40 are connected in parallel to the output terminal. The rectifier 20 receives AC power from the commercial power supply 10, converts the AC power into DC power, charges the storage battery 30, and supplies power to the load 40. Further, when the commercial power source 10 is out of power, when the rectifier 20 is out of order, and when the load 40 is overloaded, the storage battery 30 is discharged, so that power is continuously supplied to the load 40 without instantaneous interruption.

Generally, a storage battery is used in the form of an assembled battery in which several unit cells or unit cells are connected in series. Taking a lead-acid battery with a nominal voltage of 2V / cell as an example, 24 unit cells (2
4 cells) are connected in series to be used as a 48V battery pack, or 9 unit batteries (54 cells) having a 6-cell configuration are connected in series to be used as a 100V battery pack. FIG.
The storage battery 30 of is also an assembled battery.

As is well known, the actual capacity of a storage battery gradually decreases as it ages, and eventually it reaches the end of its useful life. In the system of FIG. 4, when the actual capacity of the storage battery 30 decreases due to deterioration over time, power supply to the load 40 may not be possible when the commercial power supply 10 fails.
Therefore, in order to ensure the reliability of the system, it is important to periodically check the deterioration status of the storage battery and replace it with a new one if there is a deterioration.

Various methods have been proposed as a method of grasping the deterioration state of the storage battery, but one of the promising methods is a method of measuring the internal resistance of the storage battery. This is because a deteriorated storage battery generally has a large internal resistance. Therefore, some devices for measuring the internal resistance of the storage battery have been proposed.

FIG. 5 is a block diagram showing the structure of a conventional storage battery internal resistance measuring device. In this figure, 100 is a storage battery internal resistance measuring device, and 31 is a storage battery to be measured by the storage battery internal resistance measuring device 100. The storage battery internal resistance measuring device 100 includes a device body 101 and a connecting means 1.
10, the apparatus main body 101 further includes a voltage measuring unit 120, a current generating unit 130, and an arithmetic / control unit 1.
40 and an operation / display means 150. In addition,
The storage battery 31 to be measured often has to be a single battery or a unit battery.

The connecting means 110 is for connecting the apparatus main body 101 to the terminals of the storage battery 31, and has at least an anode electric path and a cathode electric path. Actually, the storage battery 3
Since the internal resistance of 1 is extremely small, an anode voltage circuit, an anode current circuit, a cathode voltage circuit, and a cathode current circuit are often provided for performing four-terminal measurement.

The voltage measuring means 120 measures the terminal voltage of the storage battery 31 through the connecting means 110, and the current generating means 13
0 causes a current to flow through the storage battery 31 through the connection means 110.
The calculation / control means 140 is a storage battery internal resistance measuring device 100.
It controls the operation of each of the above parts and performs the calculation required for the operation. Further, the operation / display means 150 processes an operation input for operating the storage battery internal resistance measuring apparatus 100 and a display output for displaying the measurement result of the storage battery internal resistance measuring apparatus 100.

FIG. 6 is a flow chart showing an operation procedure of a conventional storage battery internal resistance measuring apparatus. To make a measurement
First, a person connects the connecting means 110 to the terminal of the storage battery 31,
Next, the operation / display means 150 is operated. Then, the calculation
The control means 140 receives the operation input from the operation / display means 150 and controls the operation of each part of the storage battery internal resistance measuring device 100 as follows.

First, the terminal voltage of the storage battery 31 is measured by the voltage measuring means 120 and stored as V1.
Next, the current generator 130 causes a predetermined current I to flow through the storage battery 31. After waiting for a predetermined time in this state,
The terminal voltage of the storage battery 31 is measured again by the voltage measuring means 120, and this is stored as V2. Current generation means 1
30 stops the current I after measuring V2. The calculation / control means 140 first finds V2-V1 and sets it as ΔV, then divides the absolute value of ΔV by I to find the internal resistance R of the storage battery 31. The obtained R is displayed on the operation / display means 150.

The current supplied to the storage battery 31 by the current generating means 130 may be a charging current or a discharging current. When the current is the charging current, the terminal voltage of the storage battery 31 transiently rises, so that V1 <V2 (ΔV> 0), and when the current is the discharging current, it drops on the contrary, so V1> V
2 (ΔV <0). In any case, since the voltage change ΔV proportional to the internal resistance R appears in the terminal voltage of the storage battery 31 by passing the current I, R is obtained by measuring ΔV. FIG. 7 shows an operation waveform diagram of a conventional storage battery internal resistance measuring device when the current I is a discharge current.

[0012]

In the above-mentioned conventional technique, the terminal voltage V1 of the storage battery 31 before the predetermined current I is passed.
And the terminal voltage V2 of the storage battery 31 when a predetermined current I is flowing, V2−V1 is obtained and this is ΔV, and the absolute value of ΔV is divided by I to determine the internal resistance R of the storage battery 31.
Was seeking. That is, ΔV is based on the logic that the voltage change occurs in the internal resistance R when the current I flows.

If a ripple component is superimposed on the terminal voltage of the storage battery 31 for some reason, a ripple component unrelated to the current I is added to the voltage change generated in the internal resistance R when the current I flows. , ΔV is included in the measurement. FIG. 8 shows an operation waveform diagram of a conventional storage battery internal resistance measuring device when a ripple component is superimposed on the terminal voltage of the storage battery 31. In this case, ΔV obtained by V2-V1 is the voltage change ΔV1 and the ripple component ΔV.
It becomes the vector sum with 2. The value obtained by dividing the absolute value of ΔV by I will be different from the value of R to be obtained.

The storage battery is used by being connected to a rectifier or load as shown in FIG. 4, but the ripple component superimposed on the storage battery differs depending on the type of the rectifier or load connected. For example, in the power supply system for communication, since the switching rectifier is connected to minimize the ripple component, the internal resistance of the storage battery can be measured with sufficient accuracy in practical use even with the above-mentioned conventional technique. However, when a thyristor rectifier is connected or an inverter is connected as a load, a ripple component having a non-negligible amount is superimposed on the storage battery, so that the internal resistance of the storage battery cannot be accurately measured by the above-described conventional technique. There was a problem.

An object of the present invention is to provide a second voltage measuring means for measuring the terminal voltage of the second storage battery, measure the ripple component separately, and carry out a calculation for removing the ripple component by the calculation / control means. Accordingly, it is an object of the present invention to provide a storage battery internal resistance measuring device with improved measurement accuracy.

[0016]

In order to achieve the above-mentioned object, in the present invention, the second connecting means for connecting to the terminal of the second storage battery, and the terminal of the second storage battery through the second connecting means. A second voltage measuring unit that measures a voltage and a current generating unit 130 cause a current to flow through the first storage battery 31, and then the first voltage measuring unit 120 causes the first storage battery 31.
And the terminal voltage of the second storage battery is measured by the second voltage measuring means, and the change ΔV of the terminal voltage of the first storage battery 31 measured by the first voltage measuring means 120 is calculated. , Second measured by the second voltage measuring means
The calculation / control means 140 for obtaining the internal resistance of the first storage battery 31 by subtracting and correcting the change in the terminal voltage of the storage battery of 1.

[0017]

In the storage battery internal resistance measuring device according to the present invention, the first voltage measuring means 120 and the current generating means 130 are the first
Is connected to the terminal of the first storage battery 31 through the connecting means 110, and the second voltage measuring means is connected to the terminal of the second storage battery through the second connecting means. Then, first, the terminal voltage V1 of the first storage battery 31 and the terminal voltage of the second storage battery 31 before the current generation unit 130 supplies the predetermined current I to the first storage battery 31, The second voltage measuring means measures each. Next, the current generating means 13
The terminal voltage V2 of the first storage battery 31 and the terminal voltage of the second storage battery 31 when 0 is flowing a predetermined current I in the first storage battery 31 are the first voltage measuring means 120 and the second voltage. Each measuring means measures. The arithmetic / control means 140 is
First storage battery 3 measured by the first voltage measuring means 120
The internal resistance R of the first storage battery 31 is obtained by subtracting and correcting the change ΔV of the terminal voltage of 1 by the change of the terminal voltage of the second storage battery measured by the second voltage measuring means.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the structure of a storage battery internal resistance measuring apparatus embodying the present invention. In this figure, the elements common to those in FIG. Incidentally, 31 is a first storage battery, which is shown in FIG.
Of the storage battery 31, and 110 is a first connecting means which is also common to the connecting means 110 of FIG.
Reference numeral 120 denotes a first voltage measuring means, which is common to the voltage measuring means 120 shown in FIG. In each case, the word "first" is simply added for the purpose of explanation.

In FIG. 1, reference numeral 32 denotes a storage battery which belongs to the same battery pack as the first storage battery 31 and which is a second measurement target of the storage battery internal resistance measuring apparatus 100. The storage battery internal resistance measuring apparatus 100 includes a second connecting means 111 in addition to the apparatus main body 101 and the first connecting means 110, and the apparatus main body 101 further includes the first voltage measuring means 12
0, current generation means 130, calculation / control means 140, operation / display means 150, and second voltage measurement means 121.
It has. The second connecting means 111 is the apparatus main body 101.
Is connected to the terminal of the second storage battery 32, and includes an anode electric path and a cathode electric path. The second voltage measuring means 121 measures the terminal voltage of the second storage battery 32 through the second connecting means 111.

FIG. 2 is a flow chart showing the operation procedure of the storage battery internal resistance measuring apparatus embodying the present invention. In order to perform the measurement, first, a person connects the first connecting means 110 to the terminal of the first storage battery 31, and further connects the second connecting means 111 to the terminal of the second storage battery 32 to operate / display. Means 1
Operate 50. Then, the calculation / control means 140 receives the operation input from the operation / display means 150, and controls the operation of each part of the storage battery internal resistance measuring apparatus 100 as follows.

First, the terminal voltage of the first storage battery 31 is measured by the first voltage measuring means 120 and, at the same time, the second voltage is measured.
The voltage measuring means 121 measures the terminal voltage of the second storage battery 32, and stores the former as V1 and the latter as V3. Next, by the current generating means 130, the first storage battery 3
A predetermined current I is passed through 1. In this state, after waiting for a predetermined time, the first voltage measuring means 120 again causes the first voltage to be measured.
The terminal voltage of the storage battery 31 of
The voltage measuring means 121 measures the terminal voltage of the second storage battery 32, and stores the former as V2 and the latter as V4. The current generating means 130 stops the current I after measuring V2 and V4. The calculation / control means 140 first determines V2-
V1 and V4-V3 are obtained, and the former is ΔV and the latter is ΔV.
V2. Next, ΔV−ΔV2 is obtained, this is set to ΔV1, and the absolute value of ΔV1 is divided by I to obtain the internal resistance R of the first storage battery 31. The obtained R is displayed on the operation / display means 150.

FIG. 3 is an operation waveform diagram of the storage battery internal resistance measuring apparatus embodying the present invention. Δ obtained by V4-V3
V2 is a ripple component superimposed on the terminal voltage of the second storage battery 32 during the measurement of V3, that is, the measurement of V1 to the measurement of V4, that is, the measurement of V2. Since the first storage battery 31 and the second storage battery 32 belong to the same assembled battery, the superimposed ripple components have almost the same value. Therefore, the ripple component superimposed on the terminal voltage of the first storage battery 31 from the time of measuring V1 to the time of measuring V2 can be approximated by ΔV2.

On the other hand, ΔV obtained by V2-V1 is the vector sum of the voltage change generated in the internal resistance R of the first storage battery 31 due to the flow of the predetermined current I and the ripple component ΔV2 described above. Become. That is, assuming that the voltage change is ΔV1, ΔV = ΔV1 + ΔV2. Therefore, the value obtained by dividing the absolute value of ΔV by I will be different from the value of R to be obtained. Therefore, ΔV-ΔV2
ΔV1 is obtained by dividing the absolute value of ΔV1 by I to obtain the internal resistance R of the first storage battery 31.

[0025]

According to the present invention, when the internal resistance of the storage battery is obtained, the calculation for removing the ripple component superimposed on the terminal voltage of the storage battery is performed, so that the internal resistance of the storage battery can be accurately measured. become. In particular, depending on the type of rectifier or load connected to the storage battery, the internal resistance of the storage battery may not be practically measured by the conventional technique, so that the effect of the present invention for improving the measurement accuracy becomes extremely large.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a storage battery internal resistance measuring device of the present invention.

FIG. 2 is a flowchart showing an operation procedure of the storage battery internal resistance measuring device of the present invention.

FIG. 3 is an operation waveform diagram of the storage battery internal resistance measuring device of the present invention.

FIG. 4 is a system configuration diagram showing a usage example of a storage battery.

FIG. 5 is a block diagram showing a configuration of a conventional storage battery internal resistance measuring device.

FIG. 6 is a flowchart showing an operation procedure of a conventional storage battery internal resistance measuring device.

FIG. 7 is an operation waveform diagram of a conventional storage battery internal resistance measuring device.

FIG. 8 is an operation waveform diagram of a conventional storage battery internal resistance measuring device when a ripple component is superimposed on the storage battery terminal voltage.

[Explanation of symbols]

 31 first storage battery 32 second storage battery 100 storage battery internal resistance measuring device 101 device body 110 first connecting means 111 second connecting means 120 first voltage measuring means 121 second voltage measuring means 130 current generating means 140 Arithmetic / control means 150 Operation / display means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukio Tada No. 1 Nishinosho-Inaba Babacho, Kichijoin, Minami-ku, Kyoto, Japan Battery Co., Ltd. Nobabacho No. 1 Japan Battery Co., Ltd. (72) Inventor Yoshitaka Konya 1-43 Roppongi, Minato-ku, Tokyo NTT Corporation (72) Inventor Kazuo Takano Roppongi, Minato-ku, Tokyo 1-34, Inc. NTT FACILITIES, INC. (72) Inventor, Teruichi Takasaki 1-34, Roppongi, Minato-ku, Tokyo NTT FACILITIES INC.

Claims (1)

[Claims] 1. A first connecting means for connecting to a terminal of a first storage battery, and the first connecting means through the first connecting means.
First voltage measuring means for measuring the terminal voltage of the storage battery of
A current generating means for supplying a current to the first storage battery through the first connecting means; and a first voltage measuring means for supplying the current to the first storage battery by the current generating means. A storage battery internal resistance measuring device, comprising: a calculation / control means for determining an internal resistance of the first storage battery by measuring a terminal voltage of the storage battery; and a second connecting means for connecting to a terminal of the second storage battery. , The second
Second voltage measuring means for measuring the terminal voltage of the second storage battery through the connection means, and the first voltage measuring means for supplying the current to the first storage battery by the current generating means. And measuring the terminal voltage of the first storage battery, measuring the terminal voltage of the second storage battery by the second voltage measuring means, and measuring the terminal voltage of the first storage battery by the first voltage measuring means. By subtracting and correcting the variation of the terminal voltage of the second storage battery measured by the second voltage measuring means to obtain the internal resistance of the first storage battery. A storage battery internal resistance measuring device, comprising: