JP2002357625A - Voltage detecting circuit for storage element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a voltage detecting circuit for storage elements capable of reducing the manufacturing cost, current consumption, and a circuit area. SOLUTION: This voltage detecting circuit for the storage elements which detects the voltage between respective terminals of the multiple storage elements B1 , B2 ,...Bn connected in series are provided with voltage detecting means VD1 , VD2 ,...VDn connected to the respective terminals of the multiple storage elements and detecting currents flow from their output terminals when reaching a prescribed voltage, and a single detecting signal output means PC connected between the output terminals of the voltage detecting means and negative electrode terminals of the storage elements positioned on the lowest potential side in the multiple storage elements connected in series via load resistances R1 , R2 ,...Rn .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage detecting circuit for a storage element, and more particularly, to monitoring a voltage of each storage element of a series-connected storage element and detecting a voltage abnormality when the voltage deviates from a prescribed value. The present invention relates to a voltage detection circuit that outputs a detection signal that indicates

[0002]

2. Description of the Related Art For example, batteries such as electric vehicles and forklifts have a configuration in which a plurality of power storage elements are connected in series to obtain a high voltage. In such a battery in which a plurality of power storage elements are connected in series, a voltage abnormality occurs due to failure or wear of the power storage elements, and the performance of the battery may be impaired.

For this reason, it is necessary to provide a voltage detection circuit for the storage element. The voltage detection circuit of the power storage element monitors the voltage of each power storage element, and outputs a detection signal indicating a voltage abnormality when the voltage deviates from a prescribed value. Hereinafter, an example of a conventional voltage detection circuit for a storage element will be described with reference to the drawings. FIG. 2 is a diagram showing a configuration of a conventional voltage detection circuit of a storage element.

As shown in FIG. 2, a conventional voltage detection circuit for a storage element includes a plurality of storage elements 211 and 212 connected in series, and a voltage detection circuit is provided between a positive terminal and a negative terminal of each storage element. Means 221 and 222 are connected.
Output terminals of the voltage detectors 221 and 222 are connected to photocouplers 231 and 232, respectively.
Outputs of these photocouplers 231 and 232 are connected so as to be connected to detection terminals a and b. As described above, through the isolator such as the photocoupler, the storage element and the external circuit are electrically insulated from each other, and the detection signal is output.

Although not shown, the negative terminal of the storage element 212 is connected to the positive terminal of the next storage element, and this operation is repeated to connect a large number of storage elements in series. Each of the power storage elements is connected to a voltage detection unit and a photocoupler, and is connected so as to connect the output of each photocoupler to the detection terminals a and b.

The voltage detector 221 includes resistors 241 and 26
1, 271, a constant voltage diode 251, a voltage comparator 291, and a resistor 281. The voltage comparator 291 compares the voltage divided by the resistors 261 and 271 for dividing the voltage between the terminals of the power storage element 211 with the voltage divided by the resistor 241 and the constant voltage diode 251. It is connected. The voltage detector 222 and a voltage detector corresponding to a power storage element (not shown) have the same configuration.

Hereinafter, the operation of the conventional voltage detecting circuit for a storage element will be described. The voltage between the terminals of the storage element 211 is (resistances 241, 261, 271 and constant voltage diode 25
When the voltage reaches a predetermined voltage (preliminarily set by each resistance value of No. 1), the output of the comparator 291 becomes “H” level, and a current flows through the light emitting element of the photocoupler 231 to emit light. And a detection signal is output between the detection terminals a and b. The operation of the electric storage element 212 and the electric storage elements of the next and subsequent stages (not shown) is the same, and a detection signal can be output between the detection terminals a and b.

[0008]

However, in the conventional voltage detecting circuit for a storage element, one photocoupler corresponding to the voltage is required to detect the voltage of one storage element. The same number of photocouplers as the number of elements were required. Since this photocoupler is a relatively expensive element, the conventional voltage detection circuit for a power storage element has a problem that the manufacturing cost is high.

Further, the outputs of the light receiving elements of all the photocouplers are connected to the detection terminals a and b, respectively.
R connection) (on the detection signal output means side,
OR connection must be performed), and there is a problem that the wiring area increases and the circuit area increases.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a voltage detection circuit of a power storage element that can reduce the manufacturing cost and the circuit area.

[0011]

According to a first aspect of the present invention, there is provided a voltage detecting circuit for a storage element, comprising: a plurality of storage elements connected in series; A voltage detecting circuit of a power storage element for detecting a voltage between terminals, the voltage detection means being connected between respective terminals of the plurality of power storage elements, and a detection current flowing from an output terminal when a predetermined voltage is reached. And between the other end of the resistor having one end connected to the output terminal of the voltage detecting means and the negative terminal of the storage element located at the lowest potential side of the plurality of storage elements connected in series. And one detection signal output means for outputting a detection signal. Thus, even when any of the storage elements reaches a predetermined voltage set in advance, a single detection signal output unit can supply a current sufficient to output a detection signal. Since only one detection signal output unit is required, manufacturing costs can be reduced. Also, the detection signal output is set to O
Since no R connection is made, the circuit area can be reduced.

[0012] A voltage detection circuit for a storage element according to the present invention comprises:
As described in claim 2, the load resistance is connected between output terminals of the voltage detection means, and the load resistance is connected in series. Thus, each load resistor only needs to have a resistance value corresponding to one power storage element, and it is not necessary to use a load resistance having a high resistance value even if the combined voltage of a plurality of power storage elements becomes high.

[0013] A voltage detection circuit for a storage element according to the present invention comprises:
As described in claim 3, a block having a specific structure provided with one of the voltage detection means and one of the load resistors,
The power storage device is provided between terminals of the power storage device. Accordingly, a printed circuit board provided with a specific structure as a mounting pattern on a printed circuit board or the like and having the same wiring pattern and the same through hole position can be used. Alternatively, IC modules having the same configuration can be used.

[0014] A voltage detection circuit for a storage element according to the present invention comprises:
As described in claim 4, the block having the specific structure has a structure in which the detection signal output unit can be mounted. With this, the mounting pattern of the detection signal output means is provided on a printed circuit board or the like, and the detection signal output means is mounted only on the block corresponding to the lowest potential side storage element of the plurality of storage elements connected in series. However, it can be prevented from being implemented in other blocks. Therefore, regardless of whether or not the detection signal output means is implemented,
The same printed circuit board can be used.

[0015] A voltage detection circuit for a power storage element according to the present invention comprises:
As described in claim 5, a diode is provided in an output stage of the voltage detecting means. Thus, it is possible to prevent a current from flowing backward from the output terminal to the voltage detecting means when the voltage balance of each storage element is lost.

A voltage detection circuit for a power storage element according to the present invention comprises:
As described in claim 6, the detection signal output means,
It is a photocoupler. As described above, the electric storage element and the external circuit can be electrically insulated through the isolator such as the photocoupler.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration of a voltage detection circuit of a storage element according to an embodiment of the present invention. As shown in FIG. 1, n storage elements B1, B2,
.., Bn are connected in series. Voltage detection units (voltage detection means) VD1, VD2,... For detecting abnormal voltage values of individual storage elements.
.., VDn are provided for each storage element.

The voltage detector VD1 includes a resistor r11, a resistor r
21, a resistor r31, a constant voltage diode ZD1, a voltage comparator IC1, a resistor r41, a resistor r51, a transistor TR1, and a diode D1. The voltage comparator IC1 compares the voltage divided by the resistors r21 and r31 for dividing the voltage between the terminals of the electric storage element B1 with the voltage divided by the resistor r11 and the constant voltage diode ZD1. It is connected.

Considering how much the voltage of power storage element B1 is abnormal from the prescribed voltage value of power storage element B1, the resistances r11, r21, r31, constant voltage diode Z
Each resistance value of D1 is set. Thus, a predetermined voltage at which the voltage comparator IC1 operates is determined.

The output of the voltage comparator IC1 is a resistor r
The transistor TR1 is connected to the base of the transistor TR1 via 41, and the emitter of the transistor TR1 is connected to the positive terminal of the storage element B1. Note that a resistor r51 is inserted between the emitter and the base of TR1.

Further, the collector of TR1 is connected to the anode of diode D1, and the cathode of diode D1, which is the output of voltage detector VD1, is connected to the first terminal of load resistor R1.

The voltage detector VD2 includes a resistor r12, a resistor r
22, a resistor r32, a constant voltage diode ZD2, a voltage comparator IC2, a resistor r42, a resistor r52, and a transistor TR2. These elements are configured in the same manner as the above-described voltage detection unit VD1.
The cathode of the diode D2 serving as the output stage of No. 2 is connected to the second terminal of the load resistor R1 and to the first terminal of the load resistor R2.

It should be noted that, like the above-described voltage detection unit VD1,
Considering how much the voltage of storage element B2 is abnormal from the prescribed voltage value of storage element B2, the resistance r1
2, r22, r32, and the resistance value of the constant voltage diode ZD2. Thereby, the voltage comparator IC
2 is set to a predetermined voltage.

The voltage detector VDn provided for the n-th storage element Bn includes a resistor r1n, a resistor r2n, and a resistor r2.
3n, constant voltage diode ZDn, voltage comparator IC
n, a resistor r4n, a resistor r5n, and a transistor TRn. These elements are configured in the same manner as the above-described voltage detection unit VD1, and the cathode of the diode Dn, which is the output of the voltage detection unit VDn, is connected to the second terminal of the load resistance immediately before the load resistance Rn. And to the first terminal of the load resistor Rn.

It should be noted that the voltage detector VD1 or VD
Similarly to 2, the resistors r1n, r2n, r3n, and the constant voltage diode Z take into consideration how much the voltage of the power storage element Bn is abnormal from the prescribed voltage value of the power storage element Bn.
Each resistance value of Dn is set. As a result, a predetermined voltage at which the voltage comparator ICn operates is determined.

The second terminal of the load resistor Rn is connected to the anode of the light emitting element of the photocoupler PC (detection signal output means), and its cathode is connected to the negative terminal of the nth power storage element Bn. Detection terminals A and B are connected to the light receiving element of the photocoupler PC, and a detection signal is output when the voltage of the power storage element becomes an abnormal value.

Next, the operation of this embodiment will be described. When the voltage between the terminals of the storage element B1 is equal to the resistance r11, r21, r
31, when a predetermined voltage preset by each resistance value of the constant voltage diode ZD1 is reached, a voltage comparator IC
1 goes to the “L” level, and the transistor TR1 is turned on. As a result, the diode D1 is forward-biased, and a current flows through the light-emitting element of the photocoupler PC through the load resistors R1, R2,..., Rn to emit light. A detection signal is output between A and B. By outputting this detection signal, it can be seen that the voltage of power storage element B1 has deviated from the prescribed value, and the voltage has become abnormal.

Also, when the voltage between the terminals of the storage element B2 reaches a predetermined voltage (preset by the resistance values of the resistors r12, r22, r32 and the constant voltage diode ZD2), the above-mentioned storage element B1 is also charged. Similarly to the case, the output of the voltage comparator IC2 becomes "L" level, and the transistor TR2 is turned on. This allows the diode D2
Is forward-biased, and a current flows through the light-emitting element of the photocoupler PC through the load resistors R2,..., Rn to emit light. Is output. By outputting this detection signal, it can be seen that the voltage of power storage element B2 has deviated from the prescribed value, and the voltage has become abnormal.

Also, when the voltage between the terminals of the storage element Bn reaches a predetermined voltage (predetermined by the resistance values of the resistors r1n, r2n, r3n and the constant voltage diode ZDn), the above-mentioned storage element Bn Similarly to the case, the output of the voltage comparator ICn becomes “L” level, and the transistor TRn is turned on. Thereby, the diode Dn
Is forward-biased, and a current flows through the light-emitting element of the photocoupler PC through the load resistor Rn to emit light.
A current flows through the light receiving element C and a detection signal is output between the detection terminals A and B. By outputting this detection signal, it can be seen that the voltage of power storage element Bn has deviated from the prescribed value, and the voltage has become abnormal.

Similarly to the above-described power storage elements B1, B2, and Bn, in any of the power storage elements (not shown), when the voltage between the terminals reaches a predetermined voltage. , A current flows through the light receiving element of the PC, and a detection signal is output between the detection terminals A and B.

If all the storage elements are in a normal state and the voltage between the terminals of all the storage elements has not reached the predetermined voltage, the transistors TR1, TR2,.
.., TRn are all in the off state, so that the current consumption from the storage element can be reduced.

In this embodiment, the resistance values of the load resistors R1, R2,..., Rn connected in series are adjusted to the optimum values corresponding to the respective storage elements B1, B2,. (For example, if the voltage values of all the storage elements are the same, load resistances R1, R2,.
..., Rn are all set to the same resistance value), and the PC supplies a sufficient current for the light emitting element to emit light even when any of the electric storage elements reaches a predetermined voltage set in advance. Can be.

In this embodiment, one voltage detecting means and one voltage detecting means
One load resistor may be a block having a specific structure, and may be provided on a printed board or the like as a mounting pattern having a specific structure. In this case, since each block has the same circuit configuration,
A printed circuit board having the same wiring pattern and the same through hole position can be used, and the manufacturing cost of the printed circuit board can be reduced. Note that the block having the specific structure is represented by I
It may be configured by a C-converted module.

The photocoupler PC must be connected to the voltage detector VDn and the load resistor Rn provided for the n-th storage element Bn. Pattern is provided, and n
It is sufficient to mount the photocoupler PC only on the individual block (no photocoupler is mounted on other blocks).

In this embodiment, the load resistors R1, R2,.
, Rn are connected in series, but the load resistances R are connected so that one load resistance is connected to one storage element.
, Rn, ..., Rn can be connected in parallel. That is, the load resistance inserted between the output of the voltage detection unit VD1 and the photocoupler PC is only R1, and the second terminal of the load resistance R1 is directly connected to the anode of the light emitting element of the photocoupler PC. Other voltage detectors VD2,
,..., VDn outputs are also load resistors R2,.
In this configuration, each of them is connected to the anode of the light emitting element of the photocoupler PC via only n. In this case, for example, a voltage obtained by adding the voltage values of the n power storage elements is added to the load resistor R1, so that the load resistor R1 needs to have a high resistance. Each of the load resistors R2,..., Rn is added with a voltage obtained by adding the voltage values of a plurality of power storage elements, and a resistor having a resistance value corresponding to the voltage must be prepared.

In this embodiment, the load resistors R1, R2,.
.., Rn are connected in series, so that each load resistance may be a resistance value corresponding to one storage element.
It is not necessary to use a load resistor having a high resistance value as in the case where the load resistors are connected in parallel.

[0037]

According to the present invention, there is provided a voltage detecting circuit for a power storage element for detecting a voltage between respective terminals of a plurality of power storage elements connected in series. A voltage detecting means connected between the terminals of the plurality of power storage elements and having a detection current flowing from an output terminal when a predetermined voltage is reached; and a resistor having one end connected to the output terminal of the voltage detecting means. One detection signal output unit that outputs a detection signal by being inserted between the storage device and the negative terminal of the storage device located on the lowest potential side of the plurality of storage devices connected in series, Even when the power storage element reaches a predetermined voltage set in advance, the single detection signal output means can supply a sufficient current to output the detection signal, and the detection signal output means To reduce manufacturing costs. Rukoto can. Further, since the detection signal outputs are not OR-connected, the circuit area can be reduced.
Thus, a high-performance and low-cost voltage detection circuit for a power storage element can be provided.

According to the present invention, as described in claim 2, a load resistor is connected between the output terminals of the voltage detecting means, and the load resistors are connected in series.
Each load resistor only needs to have a resistance value corresponding to one power storage element. Even if the combined voltage of a plurality of power storage elements becomes a high voltage, it is not necessary to use a load resistance having a high resistance value, and at low cost, A stable voltage detection circuit for a storage element can be provided.

According to the present invention, as described in claim 3, a block having a specific structure provided with one voltage detecting means and one load resistor is provided between terminals of the electric storage element. It is possible to use a printed circuit board or an IC module having the same configuration in which the wiring pattern and the position of the through hole are the same, and to provide a voltage detection circuit of a power storage element which can be manufactured at low cost and can shorten the manufacturing period.

According to the present invention, as described in claim 4, since the blocks having the specific structure have a structure in which the detection signal output means can be mounted, the blocks have the same configuration regardless of whether the detection signal output means is mounted. It is possible to provide a voltage detection circuit of a power storage element that can use a printed circuit board or the like.

According to the present invention, as described in claim 5, a diode is provided in the output stage of the voltage detecting means, so that when the voltage of each storage element is out of balance, the voltage is output to the voltage detecting means. A highly reliable voltage detection circuit of a power storage element which can prevent a current from flowing backward from a terminal can be provided.

According to the present invention, as set forth in claim 6, the detection signal output means electrically insulates between the electric storage element and the external circuit via an isolator such as a photocoupler. It is possible to provide a voltage detection circuit for a storage element with high safety that can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a voltage detection circuit of a storage element according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a conventional voltage detection circuit of a storage element.

[Explanation of symbols]

 A, B detection terminals B1, B2, Bn storage element D1, D2, Dn diode IC1, IC2, ICn voltage comparator PC photocoupler R1, R2, Rn load resistance TR1, TR2, TRn transistor VD1, VD2, VDn voltage detector ZD1 , ZD2, ZDn constant voltage diode r11, r12, r1n resistance r21, r22, r2n resistance r31, r32, r3n resistance r41, r42, r4n resistance r51, r52, r5n resistance

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Nishizawa 1163 Shimohiplane, Inari-cho, Nagano City, Nagano Prefecture Inside Nagano Japan Radio Co., Ltd. (72) Inventor Fujio Matsui 1-7-2 Nishishinjuku, Shinjuku-ku, Tokyo F term (for reference) 2G016 CA03 CB11 CB12 CC01 CC04 CD09 CD14 2G035 AA12 AB03 AC16 AD02 AD04 AD08 AD11 AD23 AD33 AD56 5H030 AA06 AS06 AS08 FF43 FF44

Claims (6)

[Claims] 1. A voltage detection circuit of a power storage element for detecting a voltage between respective terminals of a plurality of power storage elements connected in series, the voltage detection circuit being connected between respective terminals of the plurality of power storage elements, A voltage detection unit that causes a detection current to flow from an output terminal when the voltage reaches a predetermined voltage; the other end of a resistor having one end connected to the output terminal of the voltage detection unit; and the lowest potential among the plurality of power storage elements connected in series. A detection signal output unit that is inserted between a negative electrode terminal of the power storage element located on the side and that outputs a detection signal, and a voltage detection circuit for the power storage element. 2. The voltage detection circuit for a storage element according to claim 1, wherein the load resistance is connected between output terminals of the voltage detection means, and the load resistance is connected in series. A voltage detection circuit for a storage element. 3. The voltage detection circuit for a power storage element according to claim 1, wherein a block having a specific structure including one voltage detection means and one load resistance is provided for each of the power storage elements. A voltage detection circuit for a storage element, provided between terminals. 4. The voltage detection circuit for a power storage element according to claim 3, wherein the block having the specific structure has a structure in which the detection signal output unit can be mounted. circuit. 5. The voltage detection circuit according to claim 1, wherein a diode is provided in an output stage of said voltage detection means. Detection circuit. 6. The voltage detection circuit for a power storage element according to claim 1, wherein said detection signal output means is a photocoupler. .