JP2000193694A - Voltage detecting device of battery set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a voltage detecting device capable of inhibiting a reduction of a detection accuracy and a safety, while realizing with a simple circuit consti tution. SOLUTION: Common terminals comprising lowest position terminals of a battery block 11 are independently connected to one end of the large number of voltage-dividing circuits, in which a plurality of resistance elements R1-R10 are connected in series through a standard potential line 3. The other ends of the respective voltage-dividing circuits are connected to high position side terminals of respective battery modules BAT01-BAT05, except for the common terminals respectively. Of a plurality of resistance elements of the respective voltage-dividing circuits, a voltage drop of the resistance elements R2, R4, R6, R8, R10 on the standard potential line side is detected. The resistance elements R2, R4, R6, R8, R10 on the standard potential line side are also used as resistance elements on the standard potential line side of a voltage-dividing circuit which detects the potential of the battery modules BAT06-BAT10 of a battery block 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembled battery voltage detecting device.

[0002]

2. Description of the Related Art Japanese Patent Laying-Open No. 5-64377 discloses an assembled battery voltage detecting device for detecting the module voltages of a plurality of battery modules composed of a large number of cascade-connected single cells with a voltage detecting module. is suggesting.

[0003]

However, individually detecting each module voltage with a large number of differential voltage detection circuits as described above requires a large-scale circuit configuration, cost, power consumption, and space. It needed to be improved in terms of reliability.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an assembled battery voltage detecting device which can be realized with a simple circuit configuration while suppressing a decrease in detection accuracy and safety. I have.

[0005]

According to the voltage detecting device for an assembled battery according to the present invention, a high-voltage assembled battery is formed by connecting a plurality of battery blocks each having a plurality of battery modules connected in series. It becomes. As the battery module, one unit cell may be used, or a plurality of unit cells may be connected in series.

In this configuration, in particular, the common terminal consisting of the highest terminal or the lowest terminal of the battery block is individually connected to one end of a number of voltage dividing circuits each having a plurality of resistance elements connected in series through a reference potential line. The other end of each voltage dividing circuit is connected to a terminal of each battery module except the common terminal, and a voltage drop of a resistance element on a reference potential line side among a plurality of resistance elements of each voltage dividing circuit is detected. You. With this configuration, the module voltage signal composed of the divided voltage output from each voltage dividing circuit in the same battery block to the module voltage detecting unit is based on the common potential formed by the potential of the reference potential line. Therefore, the subsequent circuit processing is simplified, and the module voltage can be detected with a simple circuit configuration and with little error.

More specifically, in one battery block, the potential of each battery module is detected with reference to the highest potential or the lowest potential of this battery block, so that the terminal voltage of each battery module is determined by each detected battery module. It is obtained as a potential difference. If you do this,
Rather than individually detecting the potential difference (terminal voltage) of each battery module, the power supply voltage applied to each module voltage detector can be shared, so that the power supply circuit can be simplified, The influence of variations in power supply voltage fluctuation output from the power supply circuit is also small.

However, in the above-described system in which the potential of each battery module is obtained from a potential difference from a common reference potential for each battery block and the potential difference of each battery module is calculated by subtracting the potential of each battery module, The potential of the battery module away from the potential line becomes a high voltage several times the potential difference of the battery module, for example, several tens of volts, and it is necessary to increase the withstand voltage of the input part of the module voltage detecting unit in order to detect such a high voltage. . On the other hand, in this configuration, the potential of each battery module is divided by the voltage dividing circuit based on the potential of the reference potential line (reference potential), so that the input voltage of the module voltage detecting unit is, for example, 5V. , And the module voltage detector can be constituted by general-purpose circuit elements.

According to a second aspect of the present invention, in the voltage detecting device for an assembled battery according to the first aspect, the common terminals of the first and second battery blocks adjacent to each other in potential are each provided with a changeover switch (reference potential). Each voltage dividing circuit is connected to the common reference potential line through a changeover switch, and each voltage dividing circuit has a changeover switch (module voltage changeover switch) connected in series with a plurality of resistance elements. The resistance element on the potential line side also functions as a resistance element on the side of each reference voltage line of the second battery block.

With this configuration, the potentials of a pair of battery blocks that are electrically adjacent to each other can be detected by switching the changeover switch, so that the number of module voltage detectors can be reduced by half and the voltage dividing circuit can be detected. The required number of resistance elements can be significantly reduced, and the circuit scale can be reduced.

Further, even if one of the plurality of module voltage changeover switches connected to each other is short-circuited and the remaining module voltage changeover switches are turned on, the short circuit flowing through both of the two switches may occur. Since the current is suppressed by the resistance element, the safety is excellent. In other words, the resistance of the voltage dividing circuit has the function and effect described in claim 1 and also has the effect of reducing short-circuit current.

According to a third aspect of the present invention, in the voltage detecting device for an assembled battery according to the first or second aspect, each of the voltage dividing circuits has a changeover switch connected in series with a plurality of resistance elements. The resistance element on the potential line side is common to each voltage dividing circuit.

With this configuration, the required number of the resistor elements of the module voltage detecting section and the voltage dividing circuit can be further reduced, so that the circuit size can be further reduced.

According to a fourth aspect of the present invention, in the voltage detecting device for an assembled battery according to the second or third aspect, each of the changeover switches is interposed between a plurality of resistance elements of the voltage dividing circuit to form a plurality of changeovers. Since the switches are integrated in the same circuit module, the circuit configuration can be simplified.

That is, when each switch is interposed between a plurality of resistance elements of the voltage dividing circuit, the terminal on the anti-battery module side of each switch is the terminal on the anti-battery module side of at least one other switch. Can be connected inside the circuit module, the number of external wiring lines and the connection work can be greatly reduced, and the switch circuit can be simplified.

According to the fifth aspect of the present invention, the common terminals of the first and second battery blocks which are electrically adjacent to each other are connected to the common reference potential line through the changeover switch. Each voltage dividing circuit has a backflow prevention diode connected in series with a plurality of resistance elements (voltage dividing resistors). The voltage detection circuit detects the potential of the divided voltage output terminal of each resistance voltage dividing circuit belonging to the battery block with reference to the low potential end of the battery module having the lowest potential of the battery block to be measured. At this time, the common terminal of the battery block to be measured is connected to the reference potential line by the changeover switch only at the time of measurement.

According to this configuration, the following operation and effect can be obtained.

According to this configuration, a backflow prevention diode is interposed between the battery module and the resistance voltage dividing circuit for each resistance voltage dividing circuit. It is not necessary to connect a changeover switch in series, thereby simplifying circuit manufacturing.

That is, the backflow prevention diode circulates through an arbitrary two voltage dividing circuit and a circuit including one or a plurality of battery modules by a changeover switch provided for each voltage dividing circuit. Circulating (short circuit) current can be prevented. A backflow prevention diode is much cheaper than a changeover switch, and its open / close control circuit can be omitted.

Further explanation will be given.

Since the changeover switch is connected in series with the voltage dividing circuit, the current of the voltage dividing circuit flows. As is well known, the voltage change of the battery module is small, and it is necessary to measure this small voltage change with extremely low noise. For this reason, when the resistance element of the voltage dividing circuit (and the switch and the changeover switch are connected in series, the ON state is not changed). Resistance) to reduce their resistive noise.

However, the changeover switch is a so-called transfer switch, and it is necessary to secure a withstand voltage in both directions for safety reasons. Therefore, it is difficult to make the switch by the bipolar technique, and it must be made by the MOS technique. However, it is not easy to integrate a large-sized MOS transistor as a changeover switch and a low-resistance element (usually manufactured by a bipolar technique) of a voltage dividing circuit.

On the other hand, in the present configuration, the number of necessary changeover switches is small, and a configuration using a backflow prevention diode for preventing short-circuit current is adopted. Therefore, the low-resistance voltage dividing circuit and the backflow prevention diode are bipolar. It can be easily integrated by integrated circuit technology.

According to this circuit configuration, the voltage detection circuit measures a signal voltage equal to (terminal voltage V of the battery module−forward voltage drop ΔV of the backflow prevention diode) × voltage division ratio. If the temperature is known, the amount of forward voltage drop of the backflow prevention diode can be known in advance, so that various hardware or software can be used to correct the measured value due to the variation of the backflow prevention diode voltage drop.

According to a sixth aspect of the present invention, in the voltage detecting apparatus for an assembled battery according to the fifth aspect, further, a battery block on a higher side of the pair of battery blocks connected in series and connected to each other in potential is connected. And a clamp circuit that suppresses the potential of the voltage division output terminal of the voltage division circuit connected to the battery module to which the battery module belongs to a predetermined level or less.

With this arrangement, when the potential of the voltage dividing output terminal of the resistance voltage dividing circuit connected to the battery module belonging to the lower battery block is measured by the operation of the clamp circuit, the lower battery block is used. The output voltage of the resistor voltage dividing circuit of the battery block on the higher side does not rise by the voltage obtained by multiplying the voltage dividing ratio by the voltage dividing ratio of the voltage dividing circuit. There is no need to increase.

Note that a diode, a constant voltage diode, or the like can be used as the clamp circuit.

According to a seventh aspect of the present invention, in the voltage detecting apparatus for an assembled battery according to the fifth aspect, the voltage dividing output terminals of the plurality of voltage dividing circuits are connected to the input of one voltage detecting circuit through different signal changeover switches. Connected to the end.

With this configuration, when measuring the potential of the voltage dividing output terminal of the voltage dividing circuit connected to the battery module belonging to the lower battery block, the voltage dividing circuit is added to the voltage of the lower battery block. Even if the output of the resistor divider circuit of the battery block on the higher side rises by the voltage multiplied by the division ratio of
Since the signal changeover switch is open, the input signal withstand voltage of the module voltage detecting unit for detecting the potential of the voltage dividing output terminal of the voltage dividing circuit connected to the battery module belonging to the higher battery block is increased. There is no need, and the clamp circuit can be omitted.

Furthermore, this signal changeover switch can be used as a so-called multiplexer,
There is an advantage that the number of module voltage detectors can be reduced.

Although this circuit configuration requires both a backflow prevention diode and a signal changeover switch, this signal changeover switch is different from a changeover switch connected in series with a voltage dividing circuit as described in claim 2. Essentially different, their on-resistance may be much higher. That is, this signal changeover switch only has to transmit the potential of the voltage dividing output terminal of the voltage dividing circuit to the input terminal of the module voltage detecting unit. The signal changeover switch described above can be easily constituted by a MOS integrated circuit, and such an on-resistance value is preferable because it suppresses penetration of surge noise voltage into the input terminal of the module voltage detection unit.

On the other hand, the on-resistance of the changeover switch connected in series with the voltage dividing circuit must be significantly reduced in order to suppress the resistive noise voltage. Is difficult, and it is also necessary to reduce the variation in on-resistance.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the following examples. However, the present invention is not limited to the configuration of the following embodiment, and it is obvious that the present invention can be configured using a replaceable known circuit.

[0034]

[Embodiment 1] An embodiment of a voltage detecting device for an assembled battery according to the present invention will be described with reference to a partial circuit diagram shown in FIG.

Reference numeral 1 denotes an assembled battery, which is formed by connecting a total of four battery blocks including the highest battery block 11 and the next highest battery block 12 in series. However, illustration of the remaining battery blocks is omitted. The battery block 11 has five battery modules BAT01 to BAT05 connected in series, and the battery block 12 has five battery modules BA.
T06 to BAT10 are connected in series.

Reference numeral 2 denotes resistance elements R1 to R11, R13, R
15, R17, and R19.
And R2, R3 and R4, R5 and R6, R7 and R
8, R9 and R10, R11 and R2, R13 and R
4, R15 and R6, R17 and R8, R19 and R1
0 constitutes a voltage dividing circuit. Resistance element R2,
One end of each of R4, R6, R8, and R10 (the resistance element on the reference potential line side in the present invention) is connected to the lowest potential end of the battery block 11 through the reference potential line 3 and the changeover switch SW21. 3 and the switch SW22 are connected to the lowest potential terminal of the battery block 12. Also, the resistance elements R2, R4,
The other ends of R6, R8, and R10 (the resistance elements on the reference potential line side in the present invention) are connected to resistance elements R1, R3, R5, and R, respectively.
7, R9 and the changeover switches SW1 to SW5 are connected to the higher pole of each battery module of the battery block 11. Further, resistance elements R2, R4, R6,
The other ends of R8 and R10 (the resistance elements on the reference potential line side in the present invention) are connected to resistance elements R11, R13, R15, R
17, R19 and the switches SW6 to SW10 are connected to the higher pole of each battery module of the battery block 12.

Each of the changeover switches SW1 to SW10, S
Each of W21 and SW22 is formed of a photo MOS transistor, and is opened and closed by being driven by a light signal from an LED facing each other.

4 is a module voltage detection block,
A five-channel module voltage detector is built in parallel inside, and resistance elements R2, R4, R6, R8, R10
The voltage drop of (the resistance element on the reference potential line side in the present invention) is individually detected. Each of the module voltage detectors comprises an A / D converter. Of course, an A / D converter of a type for sequentially switching a large number of input signals may be used.

This A / D converter converts the voltage difference between the divided voltage input from each of the voltage dividing circuits and the reference potential VSS into a digital signal. In one example, the A / D converter includes a reference voltage generation circuit that generates various reference voltages higher than the reference voltage VSS using the reference potential VSS as a reference potential, and a plurality of comparison circuits that compare each of the generated reference voltages with an input divided voltage. And a digital signal generation circuit for converting a signal output from the comparator into a digital signal, but detailed description thereof will be omitted.

When the voltage of the battery module of the battery block 11 is detected, the A / D converter connects the battery module B through the reference potential line 3 and the changeover switch SW21.
Receiving the reference potential VSS from the lower pole of AT05,
At this time, the changeover switch SW22 is open.
Thus, by turning on the changeover switches SW1 to SW5 and turning off the changeover switches SW6 to SW10, each battery module BAT0 of the battery block 11 is turned off.
1 to BAT05 are converted into digital signals and output to a controller (not shown), and the controller performs subtraction processing on each of the battery modules BAT01.
BAT05 is detected.

Similarly, when detecting the voltage of the battery module of the battery block 12, the changeover switches SW6 to SW1
0 is turned on, and the changeover switches SW1 to SW5 are turned off.
The potentials of the high-order poles of AT06 to BAT10 are converted into digital signals and output to a controller (not shown).
The voltage of T06 to BAT10 is detected.

According to this embodiment, the module voltage signal composed of the divided voltage output from each voltage dividing circuit in the same battery block to the module voltage detecting section is a common voltage composed of the potential of the reference potential line. Since the potential signal is based on the potential, the power supply voltage applied to each module voltage detector can be shared, so that the power supply circuit can be simplified and the module in this case can be used. Since the increase in the input signal voltage to the voltage detection unit is reduced by employing the voltage dividing circuit, the circuit configuration can be simplified while the increase in the input voltage is suppressed.

Further, in this embodiment, the resistance elements R2, R4. R6, R8, R10
Respectively constitute a part of two voltage dividing circuits, so that the number of resistance elements can be reduced.

[0044]

Embodiment 2 FIG. 4 shows another example of the module voltage detecting section constituting the module voltage detecting circuit block 4. In FIG.

This module voltage detecting section comprises a differential voltage circuit 41 and an A / D converter 42 for A / D converting the output voltage. The configuration of the other module voltage detectors is the same. The power supply voltages VH and V are supplied from the constant voltage power supply circuit 43 to each differential voltage circuit 41 and each A / D converter 42.
L is supplied.

At the time of detecting the voltage of the battery module of the battery block 11, the negative input terminal of the differential voltage circuit 41 receives the reference potential VSS from the lower pole of the battery module BAT05 through the reference potential line 3 and the changeover switch SW21. , The changeover switch SW22 is open. The power supply voltage VL output from the constant voltage power supply circuit 43 is shifted to a potential lower than the reference potential VSS,
The power supply voltage VH output from the constant voltage power supply circuit 43 is set to a potential higher than the potential (divided voltage) VCHO at the connection point between the resistance elements R1 and R2. Thereby, the changeover switches SW1 to SW5 are turned on, and the changeover switch S
By turning off W6 to SW10, the battery block 1 is turned off.
Since the potential of the higher pole of each of the battery modules BAT01 to BAT05 is input to the + input terminal of each differential voltage circuit 41, the difference is digitally converted and output to a controller (not shown). This controller detects the potential of each of the battery modules BAT01 to BAT05 by a subtraction process.

Similarly, when detecting the voltage of the battery module of the battery block 12, the negative input terminal of the differential voltage circuit 41 receives the reference potential VSS from the lower pole of the battery module BAT10 through the reference potential line 3 and the switch SW22. At this time, the changeover switch SW21
Is open. The power supply voltage VL output from the constant voltage power supply circuit 43 is shifted to a potential lower than the reference potential VSS, and the power supply voltage V
H is the potential (partial voltage) at the connection point between the resistance elements R11 and R2.
The potential is set higher than VCHO. Thus, by turning off the changeover switches SW1 to SW5 and turning on the changeover switches SW6 to SW10, each of the battery modules BAT06 to BAT of the battery block 12 is turned on.
Since the potential of the 10 higher-order poles is input to the + input terminal of each differential voltage circuit 41, the difference is digitally converted and output to a controller (not shown). This controller performs each of the battery modules BAT06 to BAT10 by subtraction processing.
Is detected.

[0048]

Embodiment 3 Another embodiment of the present invention will be described with reference to a partial circuit diagram shown in FIG.

The apparatus of this embodiment is similar to that of the first embodiment shown in FIG.
In the device described above, the voltage dividing resistors R21 and R2 are further provided between the reference potential line 3 and the changeover switches SW21 and SW22.
2 is provided. However, in this case, the resistance ratio between the resistance elements needs to be changed.

According to this embodiment, the changeover switch S
Even when one of the switches W21 and SW22 is short-circuited and the other switch is turned on, the short-circuit current flowing between the two switches SW21 and SW22 can be regulated, and safety can be improved.

[0051]

[Embodiment 4] Another embodiment of the voltage detecting apparatus for a battery pack according to the present invention will be described with reference to a partial circuit diagram shown in FIG.

The apparatus of this embodiment is the same as that of the first embodiment shown in FIG.
In this device, the connection order of the high-side resistance element group 2a composed of odd-numbered resistance elements of the voltage-dividing circuit group 2 and the switching switches SW1 to SW10 is reversed, and all the switching switches SW1 to SW10, SW21, SW22
Are provided on a common circuit board 5, and the resistance elements R2, R
4, R6, R8, and R10 (the resistance elements on the reference potential line side in the present invention) are replaced with a single resistance element Rc. Further, in this embodiment, each switch SW
1 to SW10, SW21 and SW22 are constituted by ordinary MOS transistors.

When detecting the voltage of each of the battery modules BAT01 to BAT05 of the battery block 11, the changeover switches SW1 to SW5 are turned on in time sequence.
The potential at both ends of the common resistance element Rc is detected and detected by a single module voltage detection unit. When detecting the voltage of each of the battery modules BAT06 to BAT10 of the battery block 12, the changeover switches SW6 to SW10
Are sequentially turned on, and the potential at both ends of the common resistance element Rc is detected, and this is detected by the same module voltage detection unit as described above. In this embodiment, the addition of the resistance elements R21 and R22 shown in FIG. 2 is also possible.

According to this embodiment, since an input from the outside is inputted to each of the changeover switches SW1 to SW10 through the resistance element, a voltage due to static electricity and other surge voltages are attenuated by the resistance element. There is also an advantage that the changeover switches SW1 to SW10 can be protected well.

Further, the control voltage for driving the changeover switches SW1 to SW10, SW21 and SW22 composed of MOS transistors can be reduced, and an element having a small withstand voltage (eg, gate withstand voltage) can be used. Can play. about this,
This will be further described with reference to FIG.

The changeover switch SW1 has a gate potential Vg
And a control voltage Vgs which is a difference between the control voltage Vgs and the source potential Vs. When the switch SW1 is off, the source voltage Vs is equal to the potential of the reference potential line 3, so that the switch SW1 can be operated with a small control voltage Vgs. Since the divided voltage of R1 and R2 is low, the changeover switch SW1 can be sufficiently driven even when the control voltage Vgs is small.

On the other hand, in the arrangement of the changeover switch SW1 shown in FIG. 1, after the conduction, the source voltage Vs becomes almost equal to the potential of the higher pole of the battery module BAT01. Vg
Therefore, the breakdown voltage and the channel resistance of the semiconductor switch constituting the changeover switch are significantly increased.

Further, in this embodiment, as shown in FIG. 3, one end of each of the changeover switches SW1 to SW10 is connected to a common output terminal 51 to a wiring pattern on a circuit board, and further to one chip, and to connect with the wiring inside the chip. Therefore, there is an advantage that the circuit configuration can be extremely simplified.

In the circuit of the first embodiment shown in FIG. 1, the changeover switches SW1 to SW10 and the odd-numbered resistance elements can be exchanged similarly to this embodiment.
The semiconductor switches constituting the changeover switches SW1 to SW10 can be simplified, and furthermore, the wiring can be simplified by mounting these semiconductor switches on the same circuit board.

[0060]

[Embodiment 5] Another embodiment of the voltage detecting apparatus for a battery pack according to the present invention will be described with reference to the circuit diagram shown in FIG. However,
Components having the same main functions as those of the circuit of the first embodiment may be denoted by the same reference numerals.

(Structure) 1 is an assembled battery, which has the highest battery block 11 and then the highest battery block 12. The battery block 11 has five battery modules BAT0.
1 to BAT05 connected in series.
Is formed by connecting five battery modules BAT06 to BAT10 in series.

Reference numeral 2 denotes a voltage dividing network composed of a voltage dividing circuit group 21 composed of diodes D1 to D10 and resistance elements R1 to R20, and a clamp circuit 22 composed of diodes D11 to D15. The voltage dividing circuit group 21 includes the battery block 11
Group 211 for battery block 12 and second group 212 for battery block 12
Consists of

The first group 211 includes a voltage dividing circuit in which a diode D1 and resistance elements R1 and R2 are connected in series, a voltage dividing circuit in which a diode D2 and resistance elements R3 and R4 are connected in series, a diode D3, and a resistance element. A voltage dividing circuit in which R5 and R6 are connected in series, a diode D4, a voltage dividing circuit in which resistive elements R7 and R8 are connected in series, a diode D5,
It comprises a voltage dividing circuit formed by connecting resistance elements R9 and R10 in series.

Similarly, the second group 212 includes a diode D
6, a voltage dividing circuit in which the resistance elements R11 and R12 are connected in series, a diode D7, a voltage dividing circuit in which the resistance elements R13 and R41 are connected in series, a diode D8, and the resistance element R
15 and R16 connected in series, a diode D9, a voltage divider formed by connecting resistance elements R17 and R18 in series, a diode D10, resistance elements R19 and R2.
It consists of a voltage dividing circuit in which 0s are connected in series.

The common connection end 2110 of the first group 211 and the common connection end 2120 of the second group 212 are connected to the reference potential line 3, respectively.

The common connection terminal 2110 of the first group 211 is connected to the lowest potential terminal (common terminal) of the battery block 11 through the changeover switch SW21.
Are connected to the lowest potential terminal (common terminal) of the battery block 12 through the changeover switch SW22. The high potential input terminal of each voltage divider circuit is connected to the higher pole of each of the battery modules BAT01 to BAT10,
The low potential input terminal of each voltage dividing circuit of the first group 211 is connected to the common connection terminal 2110, and the low potential input terminal of each voltage dividing circuit of the second group 212 is connected to the common connection terminal 2120.

Each of the diodes D1 to D10 is interposed between the divided voltage output terminal and the high potential input terminal of each voltage dividing circuit, and each divided voltage output terminal is connected to each module in the module voltage detection block 4. Input terminals CH0 to CH9 of the voltage detector. Each module voltage detector detects an A / D signal for detecting a potential difference between the input terminal and the reference potential line 3.
Consists of a converter.

(Operation) When detecting the voltage of the battery module of the battery block 11, the changeover switch SW21 is turned on and the changeover switch SW22 is turned off.

As a result, the input terminals CH0 to CH4 are
The voltage dividing circuit of the first group 211 applies a partial voltage of the voltage between the higher potential of each of the battery modules BAT01 to BAT05 of the battery block 11 and the reference potential line 3, and the divided voltages are A / D converted. .

At this time, a negative potential is applied from the battery block 12 to the high potential input terminal of each voltage dividing circuit of the second group 212. This negative potential is blocked by the backflow prevention diodes D6 to D10. Also, each of the backflow prevention diodes D1 to D5
Prevents short circuit of the battery module through each voltage dividing circuit.

When detecting the voltage of the battery module in the battery block 12, the changeover switch SW21 is turned off and the changeover switch SW22 is turned on.

Thus, the input terminals CH5 to CH9 are:
The voltage division circuit of the second group 212 applies a voltage division between the higher potential of each of the battery modules BAT06 to BAT10 of the battery block 12 and the reference potential line 3, and the divided voltages are A / D converted. .

At this time, the high potential input terminals of the respective voltage dividing circuits of the first group 211 are level-shifted in the positive direction by the voltage division of the voltage of the battery block 12. Input terminals CH0 to CH4 of module voltage detector
Are the diodes D11 to D1 forming the clamp circuit 22.
5, the input terminals CH0 to CH5 are clamped to the sum of VDD + the forward voltage drop of the diodes D11 to D15.
The input voltage of the module voltage detector to which a signal is input from CH4 does not become excessive.

In the module voltage detection circuit block 4, the voltage of each battery module BAT01 to BAT10 is calculated by the subtraction processing of the digital output voltage of each module voltage detection unit, that is, the A / D converter.

According to this embodiment, the module voltage signal composed of the divided voltage output from each voltage dividing circuit in the same battery block to the module voltage detecting section is a common voltage composed of the potential of the reference potential line. Since the potential signal is based on the potential, the power supply voltage applied to each module voltage detector can be shared, so that the power supply circuit can be simplified and the module in this case can be used. Since the increase in the input signal voltage to the voltage detection unit is reduced by employing the voltage dividing circuit, the circuit configuration can be simplified while the increase in the input voltage is suppressed.

Further, in this embodiment, since the voltage dividing network 2 is manufactured by the bipolar integrated circuit technology, the circuit configuration can be simplified.

[0077]

[Embodiment 6] Another embodiment of the assembled battery voltage detecting apparatus according to the present invention will be described with reference to the circuit diagram shown in FIG. However,
Components having the same main functions as those of the circuit of the fifth embodiment may be denoted by the same reference numerals.

(Structure) In the circuit shown in FIG. 7, the clamp circuit 22 is omitted from the voltage dividing network 2 shown in FIG. A circuit configuration in which the signal voltages are individually input to five input terminals CH5 to CH9 of a module voltage detection circuit block 4 composed of five channels of parallel A / D converters through individual transfer gates 51 to 60 of a multiplexer 5. Is adopted. Each of the transfer gates 51 to 60 is formed of a small MOS transistor, and forms a one-chip multiplexer circuit.

(Operation) When the voltage of the battery module of the battery block 11 is detected, the changeover switch SW21 is turned on.
The changeover switch SW22 is turned off, the transfer gates 51 to 55 are turned on, and the transfer gates 56 to 6 are turned on.
0 is turned off. When the voltage of the battery module of the battery block 12 is detected, the changeover switch SW22 is turned on, the changeover switch SW21 is turned off, the transfer gates 51 to 55 are turned off, and the transfer gates 56 to 60 are turned on.

According to this embodiment, when the voltage of the battery module of the battery block 12 is detected, the changeover switch SW2
2 is on, the changeover switch SW21 is off,
Even if the potential at the divided output terminal of the first group 211 rises, the transfer gates 51 to 55 are off, so that the input terminal of the module voltage detection circuit block 4 is not adversely affected. In addition, since the transfer gates 51 to 60 multiplex the input signal voltage, the number of A / D converters in the module voltage detection circuit block can be reduced.

(Modification) A modification of this embodiment is shown in FIG.
Shown in

In this modification, the module voltage detection circuit block 4 and the multiplexer 5 in FIG. 7 are modified.
Has only one A / D converter, and the transfer gates 51 to 60 of the multiplexer 5 connect the voltage dividing output terminals of the respective voltage dividing circuits to the input terminal CH9 of the single A / D converter.

In operation, when the voltage of the battery block 11 is detected, the transfer gate 5 is turned on with the changeover switch SW21 turned on and the changeover switch SW22 turned off.
1 to 55 are sequentially turned on, and in the voltage detection of the battery block 12, the transfer gate 56 is turned on with the changeover switch SW22 turned on and the changeover switch SW21 turned off.
To 60 may be turned on in order.

(Modification) A modification of the fifth and sixth embodiments will be described below.

In this modification, the changeover switch SW
Battery block 1 when both SW21 and SW22 are turned on
In order to prevent short-circuit of the short circuit 2, a current limiting resistor R is arranged in this short circuit as shown in FIG. In particular, when the current limiting resistor R is provided at the position shown in FIG. 9, the current limiting resistor R is used when the voltage of the main current circuit of the voltage dividing circuit , The detection accuracy of the voltage dividing circuit is not reduced. Further, the current limiting resistor R can be an element having a high resistance at a high temperature like a positive temperature coefficient thermistor, and the short-circuit current can be further limited.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an example of a battery pack voltage detecting device according to the present invention.

FIG. 2 is a circuit diagram showing another example of the assembled battery voltage detecting device of the present invention.

FIG. 3 is a circuit diagram showing another example of the assembled battery voltage detecting device of the present invention.

FIG. 4 is a block diagram illustrating an example of a circuit configuration of a module voltage detection unit.

FIG. 5 is a circuit diagram illustrating an example of a changeover switch.

FIG. 6 is a circuit diagram showing another example of the assembled battery voltage detecting device of the present invention.

FIG. 7 is a circuit diagram showing another example of the battery pack voltage detecting device of the present invention.

FIG. 8 is a circuit diagram showing another example of the battery pack voltage detecting device of the present invention.

FIG. 9 is a circuit diagram showing another example of the battery pack voltage detecting device of the present invention.

[Explanation of symbols]

1 is an assembled battery, 2 is a voltage dividing circuit group (voltage dividing network), 3 is a reference potential line, 4 is a module voltage detecting circuit block (voltage detecting circuit), R1 to R10, R11, R13, R
15, R17 and R19 are resistance elements of a voltage dividing circuit, SW1 to SW1.
SW10 is a changeover switch, SW21 and SW22 are changeover switches, 11 and 12 are battery blocks, BAT0
1 to BAT10 are battery modules, 22 is a clamp circuit

Claims (7)

[Claims] 1. A voltage detecting apparatus for a battery pack, comprising: a module voltage detecting unit for detecting a terminal voltage of each battery module from a battery pack formed by connecting a plurality of battery blocks connected in series. The common terminal comprising the highest or lowest terminal of the battery block is connected through a reference potential line to a common connection terminal which is one end of each of a number of voltage dividing circuits each having a plurality of resistance elements connected in series, The other end of each of the voltage dividing circuits is connected to a terminal of each of the battery modules except for the common terminal, and the module voltage detecting unit is configured to output the voltage of the plurality of resistance elements of each of the voltage dividing circuits. A voltage detecting device for an assembled battery, wherein a voltage drop of the resistance element on a reference potential line side is detected. 2. The voltage detecting device for an assembled battery according to claim 1, wherein the common terminals of the first and second battery blocks that are electrically adjacent to each other are connected to a common reference potential line via a changeover switch. Wherein each of the voltage dividing circuits has a switch connected in series with the plurality of resistance elements, and the resistance element on the reference potential line side of the first battery block is the second battery block. The voltage detecting device for an assembled battery also serves as the resistance element on the side of the reference potential line. 3. The voltage detecting device for an assembled battery according to claim 1, wherein each of the voltage dividing circuits has a change-over switch connected in series with the plurality of resistance elements. The voltage detection device for an assembled battery, wherein the resistance element is shared by the voltage dividing circuits. 4. The voltage detecting device for an assembled battery according to claim 2, wherein each of the changeover switches is interposed between the plurality of resistance elements of the voltage dividing circuit, and the plurality of changeover switches are the same circuit. A voltage detecting device for an assembled battery, wherein the voltage detecting device is integrated in a module. 5. The voltage detecting device for an assembled battery according to claim 1, wherein the common terminals of the first and second battery blocks that are electrically adjacent to each other are connected to a common reference potential line through a changeover switch. The voltage detecting device for a battery pack, wherein each of the voltage dividing circuits includes a backflow prevention diode connected in series with the plurality of resistance elements. 6. The voltage detecting device for an assembled battery according to claim 5, wherein the battery module is connected to the battery module belonging to the battery block on the higher side of the pair of battery blocks connected in series and connected in potential. And a clamp circuit for suppressing a potential of a voltage dividing output terminal of the voltage dividing circuit to a predetermined level or less. 7. The voltage detecting device for an assembled battery according to claim 5, wherein the voltage dividing output terminals of the plurality of voltage dividing circuits are connected to the input terminals of one voltage detecting circuit through different signal changeover switches. A voltage detecting device for an assembled battery.