JPH0799723A - Power capacitance device - Google Patents

Abstract

PURPOSE:To detect a fault in a short time by a method wherein a constant voltage source and a light emitting diode are connected in series between the terminals of each capacitor cell and the fault in each capacitor cell is detected by the luminous of the light emitting diode. CONSTITUTION:A Zener diode D1, a light emitting diode D2 and a current limiting resistor R1 are connected in series between the terminals of a capacitor cell C. Although the capacitor cell C is expressed as one capacitor, it is actually composed of a required number of electric double-layer capacitors which are arbitrary connected in series and/or in parallel with each other. A power capacitance device is composed of a number of the capacitor cells C which are arbitrary connected in series. If the terminal voltage of one of the capacitance cells C is dropped below the Zener voltage, the light emitting diode of that cell is extinguished. Therefore, the operation states of the respective capacitor cells C including their remaining charges can be monitored visually.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power storage device for electric power,
More specifically, the present invention relates to a power storage device for electric power, which includes a plurality of capacitor cells each including a predetermined number of electric double layer capacitors and is capable of detecting a failure for each capacitor cell unit.

[0002]

When an electric double layer capacitor is applied to a power storage device for electric power as a power source of an electric vehicle, for example, a large number of capacitor cells are used in combination in order to obtain a large electric capacity. Here, the capacitor cell means a unit unit including a predetermined number (one or more) of electric double layer capacitors.

[0003]

By the way, for example, 10
Assuming an electric power system in which 00 capacitor cells are combined, the mean time to failure (MTBF) per capacitor cell is 10,000 hours, that is, to operate at a failure rate of about once a year, the capacitor cell MTBF
Must be maintained at 1000 × 10000 = 10 million hours or more. This is an almost unattainable number.

Therefore, an object of the present invention is to provide a power storage device for electric power in which a plurality of capacitor cells each composed of an electric double layer capacitor are combined in an arbitrary series-parallel manner. It is to be able to detect each unit.

There are examples of using a large number of storage batteries for power facilities such as power plants or for power failure standby of telephone exchanges. In this case, the voltage and current in the assembled state of the entire device Not only is the operating state of each unit cell estimated, it is not only reliable, but there is also the problem that it takes time to locate the failed cell, and it is not possible to respond quickly.

[0006]

In order to achieve the above object, in the present invention, a plurality of capacitor cells each consisting of a predetermined number of electric double layer capacitors are provided, and the capacitor cells are connected in series and in parallel arbitrarily. In the electric power storage device, a constant voltage source and a light emitting diode are connected in series between the terminals of the capacitor cell, and a failure can be detected for each capacitor cell unit by the luminous intensity of the light emitting diode. I am trying.

In this case, as described in claim 2, a Zener diode is preferable as the constant voltage source.
Further, according to a third aspect of the present invention, the inter-terminal voltage of each capacitor cell is sequentially read out through the switching circuit at a predetermined time interval, and the inter-terminal voltage is compared with the set reference voltage. In this case, as described in claim 4, it is preferable that the set reference voltage is a previous terminal voltage read from the same capacitor cell.

Further, according to a fifth aspect of the present invention, a voltage comparator having a variable reference voltage source is connected between the terminals of each of the capacitor cells, and the reference voltage is changed at every predetermined time so that the voltage between the terminals of the capacitor cell is changed. It is characterized by comparison.

[0009]

First, according to claim 1, the voltage between the terminals of the capacitor cell is a constant voltage (zener voltage) for some reason.
The light emitting diode will be extinguished when the following occurs.

According to claims 3 and 5,
The terminal voltage of each capacitor cell is compared with the reference voltage at predetermined time intervals, and the defective cell is automatically detected within a short time.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a first embodiment of the present invention. According to this, the Zener diode D1, the light emitting diode D2 and the current limiting resistor R1 are connected in series between the terminals of the capacitor cell C. For convenience of drawing, the capacitor cell C is shown as a single capacitor, but actually it is composed of a predetermined number of electric double layer capacitors combined in an arbitrary series-parallel manner. However, depending on its capacitance, the capacitor cell C may be composed of one electric double layer capacitor.

This power storage device for electric power comprises a large number of such capacitor cells C which are connected in series and in parallel. According to the embodiment, the inter-terminal voltage is equal to or lower than the Zener voltage. Since the light emitting diode of the capacitor cell C is turned off, the operating state of the capacitor cell C including the remaining amount of each capacitor cell C can be easily known. Note that instead of the Zener diode D1, another constant voltage circuit or a constant voltage source such as a three-terminal shunt regulator may be used.

FIG. 2 shows the second embodiment, in which the voltage across the terminals of the plurality of capacitor cells C1, C2 ... Is read out to the CPU (Central Processing Unit) 12 via the switching circuit 11 at predetermined time intervals. And compared with a reference voltage.

In this case, the reference voltage is preferably the previous terminal voltage obtained from the same capacitor cell. According to this, it is possible to make a very quantitative determination of the charge / discharge capacity of the capacitor cell. You can
The determination result and the like are displayed on an appropriate display unit 13. A multiplexer or the like is used for the switching circuit 11, and a known data collection method may be applied to the data transmission method and the isolation method.

Next, a third embodiment shown in FIG. 3 will be described. The voltage comparator 14 is used for this. The voltage comparator 14 is provided with a variable reference voltage source VR on one input terminal side thereof.

The variable reference voltage source VR is, for example, the CPU 1
The reference voltage Vref is appropriately switched according to the instruction from 2. Taking the case of discharging from full charge (charged to the rated voltage (or the use voltage arbitrarily set by the user)) as an example, first, the reference voltage Vref is set to a voltage lower by ΔV than the full charge voltage. After setting and starting discharge, the time t at which the same voltage comparator 14 operates is examined.

Then, as shown in FIG.
At U12, the reference voltage Vref is decreased by ΔV at each time t, and the output of the voltage comparator 14 is monitored. If the voltage comparator 14 operates abnormally early, it means that the capacity of the capacitor cell has decreased. On the other hand, when the operation is abnormally slow, if the battery is fully charged, it is determined that the connection is abnormal. In the case of charging, the reference voltage Vref may be increased by ΔV every predetermined time.

[0018]

As described above, according to the present invention,
In a power storage device in which a large number of capacitor cells are connected in series and in parallel, a defective capacitor cell can be easily detected and automatically in a short time.

[Brief description of drawings]

FIG. 1 is a schematic circuit diagram according to a first embodiment of the present invention.

FIG. 2 is a schematic circuit diagram according to a second embodiment of the present invention.

FIG. 3 is a schematic circuit diagram according to a third embodiment of the present invention.

[Explanation of symbols]

 11 Switching Circuit 12 CPU 13 Display 14 Voltage Comparator C Capacitor Cell VR Variable Reference Voltage Source

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[Procedure amendment]

[Submission date] May 6, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Fig. 4

[Correction method] Added

[Correction content]

FIG. 4 is a graph for explaining a comparison operation of a comparator in the third embodiment.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroo Okamura 3-303-3 Minamiota-cho, Minami-ku, Yokohama-shi, Kanagawa 24 (72) Inventor Tsuyoshi Morimoto 1150 Hazawa-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Asahi Glass Co., Ltd. Chuo In the laboratory (72) Inventor Kazuya Hiratsuka 1150 Hazawa-machi, Kanagawa-ku, Yokohama-shi, Kanagawa Asahi Glass Co., Ltd. Central Research Laboratory

Claims (5)

[Claims] 1. A power storage device for electric power comprising a plurality of capacitor cells each comprising a predetermined number of electric double layer capacitors, the capacitor cells being arbitrarily connected in series and parallel,
A constant voltage source and a light emitting diode are connected in series between the terminals of the capacitor cell, and a failure can be detected for each capacitor cell unit by the luminous intensity of the light emitting diode. . 2. The power storage device according to claim 1, wherein a Zener diode is used as the constant voltage source. 3. An electric power storage device comprising a plurality of capacitor cells each comprising a predetermined number of electric double layer capacitors, the capacitor cells being arbitrarily connected in series and parallel,
By sequentially reading the inter-terminal voltage of each capacitor cell at a predetermined time interval through the switching circuit and comparing the inter-terminal voltage with the set reference voltage, it is possible to detect a failure for each capacitor cell unit. A power storage device for electric power, characterized in that 4. The power storage device according to claim 3, wherein the set reference voltage is a previous inter-terminal voltage read from the same capacitor cell. 5. A power storage device comprising a plurality of capacitor cells each comprising a predetermined number of electric double layer capacitors, the capacitor cells being arbitrarily connected in series and parallel,
Electric power characterized in that a voltage comparator having a variable reference voltage source is connected between the terminals of each of the capacitor cells, and the reference voltage is changed every predetermined time so as to be compared with the terminal voltage of the same capacitor cell. Power storage device.