JP3402583B2 - Battery cell voltage detector - Google Patents

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 Unexamined Patent Publication (Kokai) No. 5-64377 discloses a voltage detecting device for an assembled battery in which a voltage detecting module detects a module voltage of a plurality of battery modules each of which is composed of a large number of cascade-connected cells. is suggesting.

[0003]

However, the individual detection of each module voltage by a large number of differential voltage detection circuits as described above requires a large circuit configuration, which results in cost, power consumption, and space. , It needed improvement in terms of reliability.

The present invention has been made in view of the above problems, and an object thereof is to provide a voltage detecting device for an assembled battery which can be realized with a simple circuit configuration while suppressing a decrease in detection accuracy and safety. There is.

[0005]

According to the voltage detecting device for an assembled battery of the present invention as set forth in claim 1, the high voltage assembled battery comprises a plurality of battery modules connected in series and a plurality of battery blocks 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 structure, in particular, the common terminal composed of the highest or lowest terminal of the battery block is individually connected through a reference potential line to one end of a large number of voltage dividing circuits each having a plurality of resistance elements connected in series. The other end of each voltage divider circuit is connected to the terminals of each battery module except the common terminal, and the voltage drop of the resistance element on the reference potential line side is detected among the multiple resistance elements of each voltage divider circuit. It By doing so, the module voltage signal composed of the voltage divisions output from the voltage dividing circuits in the same battery block to the module voltage detection unit is based on the common potential composed of the potentials of the reference potential line. Since it becomes a potential signal to be applied, the subsequent circuit processing is simplified, and the module voltage detection with a small error can be performed with a simple circuit configuration.

To further explain, in one battery block, the potential of each battery module is detected with reference to the maximum potential or the minimum potential of this battery block. Therefore, the terminal voltage of each battery module is detected by each detected battery module. It is obtained as the difference in potential. If you do this,
Rather than detecting the potential difference (terminal voltage) of each battery module individually, the power supply voltage applied to each module voltage detection unit can be shared, so that the power supply circuit can be simplified and The influence of variations in power supply voltage output from the power supply circuit is also small.

However, in the above-mentioned method of obtaining the potential of each battery module by the potential difference from the common reference potential for each battery block and calculating the potential difference of each battery module by subtracting the potential of each battery module, The potential of the battery module distant from the potential line becomes several times higher than the potential difference of the battery module, for example, a high voltage of several tens of volts, and it is necessary to increase the withstand voltage of the input section of the module voltage detection section for detecting such a high voltage. . On the other hand, in this configuration, since the potential of each battery module is divided by the voltage dividing circuit using the potential of the reference potential line (reference potential) as a reference, the input voltage of the module voltage detection unit is, for example, 5V. And the module voltage detecting section can be configured by a general-purpose circuit element.

According to the structure described in claim 2, in the assembled battery voltage detection device according to claim 1, 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). Changeover switch) is connected to the common reference potential line, and each voltage dividing circuit has a changeover switch (module voltage changeover switch) serially connected to a plurality of resistance elements. The resistance element on the potential line side also serves as the resistance element on the line side for each reference voltage of the second battery block.

With this configuration, the potentials of the pair of battery blocks adjacent to each other in terms of potential can be detected by switching the changeover switch, so that the number of module voltage detecting sections can be reduced by half and the voltage dividing circuit 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, a short circuit that flows via both of these changeover switches is generated. Since the current is suppressed by the resistance element, the safety is excellent. That is, the resistance of the voltage dividing circuit can exert the effect of claim 1 and at the same time the effect of reducing the short-circuit current.

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

With this configuration, the required number of the resistance elements of the module voltage detecting section and the voltage dividing circuit can be further reduced, and thus the circuit scale can be further reduced.

According to the structure described in claim 4, in the voltage detecting device for the assembled battery according to claim 2 or 3, each changeover switch is provided between a plurality of resistance elements of the voltage dividing circuit, and a plurality of changeover switches are provided. Since the switches are integrated in the same circuit module, the circuit configuration can be simplified.

That is, when each changeover switch is interposed between a plurality of resistance elements of the voltage dividing circuit, the terminal on the side opposite to the battery module of each changeover switch is the terminal on the side opposite to the battery side of at least one other changeover switch. Since the wiring can be connected inside the circuit module, the number of external wiring lines and the wiring work can be significantly reduced, and the changeover switch circuit can be simplified.

According to the assembled battery voltage detecting device of the present invention, the common terminals of the first and second battery blocks adjacent to each other in terms of potential 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 voltage division output end of each resistance voltage divider circuit belonging to this battery block substantially with the low potential end of the battery module of the lowest potential of the battery block to be measured as a reference. 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.

With this configuration, the following operational effects are obtained.

According to this structure, since the backflow prevention diode is provided between the battery module and the resistance voltage dividing circuit for each resistance voltage dividing circuit, each voltage dividing circuit is arranged as in the constitution according to claim 2. Since it is not necessary to connect a changeover switch in series, the circuit manufacturing becomes simple.

That is, the backflow prevention diode circulates a circuit composed of two arbitrary voltage dividing circuits and one to a plurality of battery modules by a changeover switch provided for each voltage dividing circuit as in the structure described in claim 3. It is possible to prevent the circulating (short-circuit) current that flows. The backflow prevention diode is much cheaper than the changeover switch, and the switching control circuit thereof can be omitted.

Further description will be made.

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. Therefore, when the resistance element of the voltage dividing circuit (and the switching element and the changeover switch are connected in series, the Resistance) to reduce their resistive noise.

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

On the other hand, in the present configuration, the number of changeover switches required is small, and the configuration in which the backflow prevention diode is used for blocking the short-circuit current is adopted. Therefore, the low resistance voltage dividing circuit and this 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) × division ratio. Since the forward voltage drop amount of the backflow prevention diode can be known in advance if the temperature is known, various hardware or software can be used to correct the measurement value due to the variation in the voltage drop of the backflow prevention diode.

According to the structure of claim 6, in the voltage detecting device for the assembled battery according to claim 5, the battery block on the higher side of the pair of battery blocks connected in series adjacent to each other in potential is further connected. A clamp circuit for suppressing the potential at the voltage dividing output terminal of the voltage dividing circuit connected to the belonging battery module to a predetermined level or less is provided.

With this configuration, when the potential of the voltage dividing output terminal of the resistance voltage dividing circuit connected to the battery module belonging to the low-level battery block is measured by the operation of the clamp circuit, the low-level battery block is measured. The output voltage of the resistance voltage divider circuit of the high-level battery block does not increase in level by the voltage obtained by multiplying the voltage component of the voltage divider circuit by the voltage division ratio, and the input withstand voltage of the module voltage detector that detects that voltage is set. No need to increase.

As the clamp circuit, a diode or a constant voltage diode can be used.

According to the structure of claim 7, in the voltage detecting device for the assembled battery according to claim 5, the voltage dividing output terminals of the plurality of voltage dividing circuits are input to one voltage detecting circuit through different signal changeover switches. Connected to the end.

With this configuration, when measuring the potential at the voltage dividing output end of the voltage dividing circuit connected to the battery module belonging to the low voltage side battery block, the voltage dividing circuit is divided by the voltage of the low voltage side battery block. Even if the output of the resistance voltage divider circuit of the battery block on the high side increases by the voltage multiplied by the voltage division ratio of
Since the signal changeover switch is opened, the input signal withstand voltage of the module voltage detection unit that detects the potential of the voltage dividing output terminal of the voltage dividing circuit connected to the battery module belonging to the high-level 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,
This has the advantage that the number of module voltage detectors can be reduced.

This circuit configuration requires both the backflow prevention diode and the signal changeover switch, but this signal changeover switch is different from the changeover switch connected in series with the voltage dividing circuit as described in claim 2. Essentially different, their on-resistance can be much higher. That is, this signal changeover switch only has to transmit the potential of the voltage dividing output end of the voltage dividing circuit to the input end of the module voltage detecting portion, and there is no problem even if the ON resistance is, for example, several + k ohms or more. The signal changeover switch can be easily constructed by a MOS integrated circuit, and an ON resistance value of this level is preferable because it prevents surge noise voltage from entering the input terminal of the module voltage detecting section.

On the other hand, the changeover switch connected in series with the voltage dividing circuit must have a significantly low on-resistance in order to suppress the resistive noise voltage, and a large number of changeover switches must be integrated. However, it is also necessary to reduce variations in on-resistance.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the following examples. However, the present invention is not limited to the configurations of the following embodiments, and it goes without saying that known circuits that can be replaced can be used.

[0034]

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

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

Reference numeral 2 denotes resistance elements R1 to R11, R13, R
A voltage dividing circuit group consisting of 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
Each of 0s 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, and the reference potential line. It is connected to the lowest potential end of the battery block 12 through 3 and the changeover switch SW22. In addition, the resistance elements R2, R4,
The other ends of R6, R8, and R10 (resistance elements on the side of the reference potential line in the present invention) have resistance elements R1, R3, R5, and R, respectively.
7, R9 and changeover switches SW1 to SW5 are connected to the high-side poles of each battery module of the battery block 11. Further, the resistance elements R2, R4, R6,
The other ends of R8 and R10 (resistance elements on the side of the reference potential line in the present invention) have resistance elements R11, R13, R15 and R, respectively.
Through 17, R19 and changeover switches SW6 to SW10, they are connected to the high-side poles of each battery module of the battery block 12.

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

4 is a module voltage detection block,
A 5-channel module voltage detector is built in parallel inside, and resistance elements R2, R4, R6, R8, and R10 are included.
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 in which a large number of input signals are sequentially switched may be used.

This A / D converter converts the voltage difference between the voltage division input from each voltage dividing circuit and the reference potential VSS into a digital signal. In one example, the A / D converter includes a plurality of reference voltage generation circuits that use a reference potential VSS as a reference potential to generate various reference voltages higher than the reference potential, and a reference voltage generation circuit that compares each generated reference voltage with an input divided voltage. , And a digital signal generation circuit for converting the 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 uses the reference potential line 3 and the changeover switch SW21 to connect the battery module B to the battery module B.
Receives the reference potential VSS from the lower pole of AT05,
At this time, the changeover switch SW22 is open.
As a result, each of the battery modules BAT0 of the battery block 11 is turned on by turning on the changeover switches SW1 to SW5 and turning off the changeover switches SW6 to SW10.
The potentials of the high-order poles of 1 to BAT05 are converted into digital signals and output to a controller (not shown), and this controller performs subtraction processing on each battery module BAT01.
~ The voltage of BAT05 is detected.

Similarly, when the voltage of the battery module of the battery block 12 is detected, the changeover switches SW6 to SW1
By turning on 0 and turning off the changeover switches SW1 to SW5, each battery module B of the battery block 12
The electric potentials of the high-side poles of AT06 to BAT10 are converted into digital signals and output to a controller (not shown), and this controller performs subtraction processing on each battery module BA.
The voltage of T06 to BAT10 is detected.

According to this embodiment, the module voltage signal composed of the voltage division output from each voltage dividing circuit in the same battery block to the module voltage detecting section is the common voltage composed of the potentials of the reference potential lines. Since the potential signal is based on the potential, the power supply voltage applied to each module voltage detection unit can be shared, so that the power supply circuit can be simplified and the module in this case can be used. Since the increase of the input signal voltage to the voltage detection unit is reduced by adopting the voltage dividing circuit, it is possible to simplify the circuit configuration while suppressing the increase of the input voltage.

Further, in this embodiment, the resistance elements R2, R4. R6, R8, R10
Since each of them constitutes a part of two voltage dividing circuits, the number of resistance elements can be reduced.

[0044]

[Embodiment 2] FIG. 4 shows another example of the module voltage detecting portion constituting the module voltage detecting circuit block 4.

This module voltage detecting section comprises a differential voltage circuit 41 and an A / D converter 42 for A / D converting the output voltage thereof. The other module voltage detectors have the same structure. Each differential voltage circuit 41 and each A / D converter 42 has a constant voltage power supply circuit 43 which supplies power supply voltages VH and VH.
L has been supplied.

When the voltage of the battery module of the battery block 11 is detected, the negative input terminal of the differential voltage circuit 41 receives the reference potential VSS from the low side 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. As a result, the changeover switches SW1 to SW5 are turned on, and the changeover switch S
By turning off W6-SW10, the battery block 1
Since the potential of the high-side pole of each of the battery modules BAT01 to BAT05 of No. 1 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 potentials of the battery modules BAT01 to BAT05 by subtraction processing.

Similarly, when the voltage of the battery module of the battery block 12 is detected, the-input terminal of the differential voltage circuit 41 receives the reference potential VSS from the low side pole of the battery module BAT10 through the reference potential line 3 and the changeover 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 output from the constant voltage power supply circuit 43.
H is the potential (divided voltage) at the connection point between the resistance elements R11 and R2
The potential is set higher than VCHO. As a result, the changeover switches SW1 to SW5 are turned off and the changeover switches SW6 to SW10 are turned on, whereby the battery modules BAT06 to BAT of the battery block 12 are turned on.
Since the potential of the higher pole of 10 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 subtraction process on each battery module BAT06 to BAT10.
Detect the potential of.

[0048]

[Embodiment 3] Another embodiment of the assembled battery voltage detecting apparatus of the present invention will be described with reference to the partial circuit diagram shown in FIG.

The apparatus of this embodiment is the same as the embodiment 1 shown in FIG.
In the above device, 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 either one of W21 and SW22 has a short-circuit fault and the other changeover switch is made conductive, the short-circuit current flowing between these two changeover switches SW21 and SW22 can be regulated, and safety can be improved.

[0051]

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

The apparatus of this embodiment is the same as the embodiment 1 shown in FIG.
In this device, all the changeover switches SW1 to SW10, SW21 and SW22 are arranged such that the connection order of the high side resistance element group 2a including the odd numbered resistance elements of the voltage dividing circuit group 2 and the respective changeover switches SW1 to SW10 is reversed.
Are provided on a common circuit board 5, and the resistance elements R2, R
4, R6, R8, R10 (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 changeover switch SW
1 to SW10, SW21, and SW22 are composed of normal 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 sequentially turned on for time.
The potential across the common resistance element Rc is detected, and it is 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 detected.
Are sequentially turned on to detect the potentials across the common resistance element Rc, and the same module voltage detection unit detects the potential. In this embodiment as well, the resistance elements R21 and R22 shown in FIG. 2 can be added.

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

Further, the control voltage for driving the changeover switches SW1 to SW10, SW21, and SW22 formed of MOS transistors can be lowered, and an element having a small breakdown voltage (eg gate breakdown voltage) can be used. Can play. about this,
Further description will be given with reference to FIG.

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

On the other hand, in the arrangement of the changeover switch SW1 shown in FIG. 1, the source voltage Vs becomes almost equal to the electric potential of the high-side pole of the battery module BAT01 after conduction, and therefore the gate voltage higher than that. Vg
Therefore, the withstand voltage and channel resistance of the semiconductor switch that constitutes the changeover switch are significantly increased.

Furthermore, in this embodiment, as shown in FIG. 3, one end of each of the changeover switches SW1 to SW10 is connected to their common output end 51, and the wiring pattern on the circuit board is further made into one chip to form an on-chip wiring. Therefore, there is an advantage that the circuit configuration can be extremely simplified.

Also 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 replaced with each other as in this embodiment,
The semiconductor switches forming the changeover switches SW1 to SW10 can be simplified, and wiring can be simplified by mounting these semiconductor switches on the same circuit board.

[0060]

Fifth Embodiment Another embodiment of the assembled battery voltage detecting device of the present invention will be described with reference to the circuit diagram shown in FIG. However,
The same reference numerals may be given to components having the same main function as the circuit of the first embodiment.

(Structure) 1 is an assembled battery having a highest battery block 11 and a second highest battery block 12. The battery block 11 includes five battery modules BAT0
1 to BAT05 are connected in series, and the battery block 12
Is composed of five battery modules BAT06 to BAT10 connected in series.

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

The first group 211 includes a diode D1, a voltage dividing circuit in which resistance elements R1 and R2 are connected in series, a voltage dividing circuit in which a diode D2, 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 resistance elements R7 and R8 are connected in series, a diode D5,
It is composed of a voltage dividing circuit in which resistance elements R9 and R10 are connected in series.

Similarly, the second group 212 includes a diode D
6, a voltage dividing circuit in which resistance elements R11 and R12 are connected in series, a diode D7, a voltage dividing circuit in which resistance elements R13 and R41 are connected in series, a diode D8, and a resistance element R
15 and R16 connected in series, a voltage dividing circuit, a diode D9, resistance elements R17 and R18 connected in series, a diode D10, resistance elements R19 and R2
It consists of a voltage divider 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 end 2110 of the first group 211 is connected to the lowest potential end (common terminal) of the battery block 11 through the changeover switch SW21, and similarly, the second group 212.
The common connection end 2120 of is connected to the lowest potential end (common terminal) of the battery block 12 through the changeover switch SW22. The high potential input terminal of each voltage dividing circuit is connected to the high-side pole of each battery module BAT01 to BAT10,
The low potential input end of each voltage dividing circuit of the first group 211 is connected to the common connection end 2110, and the low potential input end of each voltage dividing circuit of the second group 212 is connected to the common connection end 2120.

Each of the diodes D1 to D10 is provided between the voltage dividing output terminal and the high potential input terminal of each voltage dividing circuit, and each voltage dividing output terminal is connected to each module in the module voltage detection block 4. Are individually connected to the input terminals CH0 to CH9 of the voltage detector. Each module voltage detection unit detects an electric potential difference between the input terminal and the reference electric potential line 3, respectively.
It consists of a converter.

(Operation) When the voltage of the battery module of the battery block 11 is detected, 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
From the voltage dividing circuit of the first group 211, a voltage division between the high potentials of the battery modules BAT01 to BAT05 of the battery block 11 and the reference potential line 3 is applied, and these voltage divisions 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, but this negative potential is blocked by the backflow prevention diodes D6 to D10. In addition, each backflow prevention diode D1 to D5
Prevents short circuit of the battery module through each voltage divider circuit.

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

As a result, at the input terminals CH5 to CH9,
From the voltage dividing circuit of the second group 212, a voltage division between the high potentials of the battery modules BAT06 to BAT10 of the battery block 12 and the reference potential line 3 is applied, and these voltage divisions are A / D converted. .

At this time, the high potential input terminals of the 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, and Input terminals CH0 to CH4 of the module voltage detector
Are the diodes D11 to D1 forming the clamp circuit 22.
5 is clamped to the sum of VDD + the forward voltage drops of the diodes D11 to D15, so that the input terminals CH0 to CH0
The input voltage of the module voltage detection unit 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 process 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, which is a voltage divider output from each voltage divider circuit in the same battery block to the module voltage detector, is the common potential of the reference potential line. Since the potential signal is based on the potential, the power supply voltage applied to each module voltage detection unit can be shared, so that the power supply circuit can be simplified and the module in this case can be used. Since the increase of the input signal voltage to the voltage detection unit is reduced by adopting the voltage dividing circuit, it is possible to simplify the circuit configuration while suppressing the increase of the input voltage.

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

[0077]

[Embodiment 6] Another embodiment of the assembled battery voltage detecting apparatus of the present invention will be described with reference to the circuit diagram shown in FIG. However,
The same reference numerals may be given to components having the same main function as the circuit of the fifth embodiment.

(Structure) The circuit shown in FIG. 7 omits the clamp circuit 22 from the voltage dividing network 2 shown in FIG. 6, and instead outputs 10 from each voltage dividing output terminal of the voltage dividing network 2. A circuit configuration in which the individual signal voltages are individually passed through the transfer gates 51 to 60 of the multiplexer 5 and input to the five input terminals CH5 to CH9 of the module voltage detection circuit block 4 including a 5-channel parallel A / D converter. Has been adopted. Each of the transfer gates 51 to 60 is composed of a small MOS transistor and is 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
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, the changeover switch SW2 is used when the voltage of the battery module of the battery block 12 is detected.
2 is on, the changeover switch SW21 is off,
Even if the potential of the voltage dividing output end of the first group 211 is increased, the transfer gates 51 to 55 are off, so that the input end of the module voltage detection circuit block 4 is not adversely affected. In addition, since these 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, and the module voltage detection circuit block 4 is 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 voltage dividing circuits to the input terminal CH9 of this one A / D converter.

In operation, when the voltage of the battery block 11 is detected, the transfer gate 5 is operated with the changeover switch SW21 turned on and the changeover switch SW22 turned off.
1 to 55 are sequentially turned on, and when the voltage of the battery block 12 is detected, the transfer gate 56 is turned on with the changeover switch SW22 turned on and the changeover switch SW21 turned off.
It suffices to turn on ~ 60 in order.

(Modification) Modifications of Examples 5 and 6 will be described below.

In this modification, the changeover switch SW
Battery block 1 when both 21 and SW22 are turned on
In order to prevent 2 from being short-circuited, 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 battery block 11 is measured and the main current circuit of the voltage dividing circuit subgroup 21 and the voltage of the battery block 12 are measured. Since it is out of the main current circuit of the voltage dividing circuit subgroup 22 in, the detection accuracy of the voltage dividing circuit is not lowered. Further, the current limiting resistor R can be an element having a high resistance at a high temperature such as a positive temperature coefficient thermistor, and can further limit the short-circuit current.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an example of an assembled battery voltage detection device of the present invention.

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

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

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

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

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

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

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

FIG. 9 is a circuit diagram showing another example of the assembled battery voltage detection 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, R19 are resistance elements of the voltage dividing circuit, SW1 to SW1.
SW10 is a changeover switch, SW21 and SW22 are changeover switches, 11 and 12 are battery blocks, and BAT0.
1 to BAT 10 is a battery module, 22 is a clamp circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-5-64377 (JP, A) JP-A-11-160371 (JP, A) JP-A-2000-134818 (JP, A) JP-A-8-140204 (JP, A) JP 8-138759 (JP, A) JP 4-299032 (JP, A) JP 10-84627 (JP, A) JP 9-15311 (JP, A) Kaihei 9-7640 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01R 19/165 G01R 31/36 H02J 7/00 302 H02J 7/02

Claims (7)

(57) [Claims] 1. A voltage detector for an assembled battery, wherein a module voltage detector detects a terminal voltage of each of the battery modules from an assembled battery formed by connecting a plurality of battery blocks connected in series to each other in series. The common terminal composed of the highest or lowest terminal of the battery block is connected through a reference potential line to a common connection terminal that is one end of each of a plurality of voltage dividing circuits in which a plurality of resistance elements are 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 the common terminal, and the module voltage detecting unit includes the plurality of resistance elements of each of the voltage dividing circuits. A voltage detecting device for an assembled battery, which detects a voltage drop of the resistance element on the reference potential line side. 2. The assembled battery voltage detecting device according to claim 1, wherein the common terminals of the first and second battery blocks that are adjacent in terms of potential are connected to a common reference potential line through a changeover switch. Each of the voltage dividing circuits has a changeover 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. 2. A voltage detecting device for an assembled battery, which doubles as the resistance element on the side of the reference potential line. 3. The assembled battery voltage detecting device according to claim 1, wherein each voltage dividing circuit has a changeover switch connected in series with each of the plurality of resistance elements, The voltage detecting device for an assembled battery, wherein the resistance element is common to the voltage dividing circuits. 4. The assembled battery voltage detection device according to claim 2, wherein each of the changeover switches is provided between the plurality of resistance elements of the voltage dividing circuit, and the plurality of changeover switches are the same circuit. A voltage detector for an assembled battery, which is integrated in a module. 5. The assembled battery voltage detection device according to claim 1, wherein the common terminals of the first and second battery blocks adjacent to each other in potential are connected to a common reference potential line through a changeover switch. The voltage detecting device for an assembled battery, wherein each of the voltage dividing circuits includes a backflow prevention diode connected in series with the plurality of resistance elements. 6. The assembled battery voltage detection device according to claim 5, wherein the battery module is connected to the battery module belonging to the higher battery block of a pair of the battery blocks that are connected in series adjacent to each other in terms of potential. A voltage detecting device for an assembled battery, comprising a clamp circuit for suppressing the potential at the 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 one input terminal of the voltage detecting circuit through different signal changeover switches. An assembled battery voltage detection device characterized by: