JP2003084015A - Flying capacitor battery pack voltage detecting circuit and driving method for it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flying capacitor voltage detecting circuit capable of reducing power consumption and detecting a disconnection failure. SOLUTION: In the flying capacitor battery pack voltage detecting circuit, a reset switch SW1 is turned on to reset a flying capacitor 3, and then according to the read out voltage of a voltage module, disconnection failure of a multiplexer 2 is determined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flying capacitor type voltage detection circuit.

[0002]

2. Description of the Related Art Electric vehicles and hybrid vehicles use a high-voltage large-capacity secondary battery that stores electric power used as running energy. Even a fuel-cell vehicle uses a high-voltage large-capacity secondary battery as a buffer for fuel cell output fluctuation. Use is considered to be suitable.

In the above application, the secondary battery is used in an assembled battery structure in which a large number of unit cells (hereinafter, also simply referred to as cells) are cascaded, and the batteries are cascaded one to consecutively for management measurement of the assembled battery. A predetermined number of cells are divided into modules, and the battery voltage is measured for each of these modules.

Japanese Laid-Open Patent Publication No. 11-248755 proposes a voltage detection technique using a flying capacitor. In this flying capacitor type voltage detection circuit, first, a pair of input side sampling switches are turned on to connect both ends of the module to both ends of the flying capacitor and sample and hold the module voltage in the flying capacitor. Next, after turning off the input side sampling switch, the pair of output side sampling switches are turned on to apply the storage voltage of the flying capacitor between the pair of input terminals of the differential amplifier circuit.

[0005]

In the above-described conventional flying capacitor type voltage detection circuit, the sampling switch increases the capacity of the flying capacitor due to the leak current when it is off, and the flying capacitor is charged by this leak current. It was necessary to reduce the voltage drop.

However, the increase in the capacity of the flying capacitor increases the power consumption of the flying capacitor type voltage detecting circuit as compared with that of other battery pack voltage detecting circuits such as the resistance voltage dividing type, and also between each module. There is a problem in that capacity variations are likely to occur.

The present invention has been made in view of the above problems, and an object thereof is to provide a flying capacitor type voltage detection circuit which realizes reduction of power consumption.

[0008]

According to a first aspect of the present invention, there is provided a flying capacitor type assembled battery voltage detection circuit which is connected in series with a flying capacitor circuit having at least one flying capacitor to form an assembled battery N (N> 2). )
A multiplexer for sequentially connecting both ends of each battery module to both ends of the flying capacitor circuit for each battery module and charging the flying capacitor circuit in the same direction by the voltage of each battery module, and a differential amplifier circuit. And a pair of output-side sampling switches that individually connect a pair of input terminals of the differential amplifier circuit to both ends of the flying capacitor circuit, the storage voltage of the flying capacitor circuit. Is read to the differential amplifier circuit through the output side sampling switch, and before the next voltage of the battery module is read into the flying capacitor circuit through the multiplexer, the flying capacitor circuit is short-circuited to store the stored voltage. Decrease It is characterized by having a reset circuit for.

The flying capacitor circuit is preferably composed of one flying capacitor or two flying capacitors connected in series. The reset circuit is preferably configured by connecting one reset switch and a short circuit current regulating discharge resistor in series.

A multiplexer preferably comprising the circuit according to claim 2 always charges the flying capacitor circuit in the same direction. Therefore, the amount of charge transferred from the battery module to the flying capacitor circuit can be reduced when the voltage of the next battery module is read due to the storage voltage remaining in the flying capacitor circuit that was charged by the previous reading of the voltage of the battery module. The discharge of the battery module can be suppressed. However, in the above-mentioned same direction readout type multiplexer,
Even if the charge transfer from the specified battery module to the flying capacitor circuit is not performed due to disconnection failure or off failure of the multiplexer circuit, the stored voltage read from the previous battery module to the flying capacitor circuit is stored in the flying capacitor circuit. Since the residual charge inevitably causes the problem of erroneously reading this residual charge as the signal voltage this time, this configuration is equipped with a reset circuit that discharges the flying capacitor circuit. After the signal voltage from the capacitor circuit to the differential amplifier circuit, this reset circuit is turned on to perform the reset operation of attenuating or erasing the stored voltage of the flying capacitor of the flying capacitor circuit by discharging. If it happens, signal Pressure and can be sorted than the voltage of the large battery modules therewith.

According to a second aspect of the present invention, in the flying capacitor type assembled battery voltage detection circuit according to the first aspect,
Each of the multiplexers has one end connected to the highest potential end, each connection end, and the lowest potential end of each battery module.
+1 number of input side sampling switches, a first switch that individually connects the other ends of the odd numbered input side sampling switches to one end of the flying capacitor circuit, and the other end of each odd numbered input side sampling switch A second switch individually connected to the other end of the flying capacitor circuit, a third switch individually connecting each other end of the even-numbered input side sampling switches to one end of the flying capacitor circuit, an even-numbered input side A current switching circuit that has a fourth switch that individually connects the other ends of the sampling switches to the other ends of the flying capacitor circuits, and that always charges the flying capacitor circuits in the same direction by the charge transfer from the battery modules. And has all the battery modules with a simple circuit configuration. It can be stored voltage in the same direction to the flying capacitor of the flying capacitor circuit.

According to a third aspect of the present invention, in the method of driving the flying capacitor type assembled battery voltage detection circuit according to the first aspect, further, based on the voltage of the battery module read immediately after the short circuit discharge operation of the reset circuit. Since the disconnection failure is determined by the above, it is possible to reliably detect the disconnection failure or the off failure of the multiplexer.
The reliability of the device is improved.

According to a fourth aspect of the present invention, in the method for driving the flying capacitor type assembled battery voltage detecting circuit according to the first aspect, the voltage of the battery module is read into the flying capacitor circuit through the multiplexer, and the flying capacitor circuit is read. The stored voltage is output to the differential amplifier circuit through the output side sampling switch, and the voltage of each battery module is sequentially read by turning off the output side sampling switch. After a certain number of read cycles, the reset circuit performs the read cycle. A short circuit discharge operation of the flying capacitor circuit is performed, and the voltage of the battery module read after the short circuit operation is sequentially changed.

The read operation of the voltage of the battery module to the flying capacitor immediately after the reset operation consumes the stored power amount (stored energy) of this battery module because the flying capacitor has no residual voltage in the same direction. Therefore, according to this configuration, since the reset operation is performed after the voltage of the battery module is applied many times, the power consumption of the battery module due to the reset operation can be reduced. Further, in this configuration, since the order of the battery modules read immediately after the reset operation is switched in order, all the battery modules can be consumed in order by the reset operation, and only a specific battery module is not consumed by the reset operation. .

According to a fifth aspect of the present invention, in the method of driving the flying capacitor type assembled battery voltage detection circuit according to the fourth aspect, the flying capacitor is partially discharged by the short circuit discharge operation of the flying capacitor circuit by the reset circuit. For example, the discharge amount is less than 50%).

According to this structure, the reset period is set such that the stored voltage of less than 50% remains in the flying capacitor even after the reset operation. In this way, it is possible to reduce the energy stored in the battery module that is lost when the voltage of the battery module is read immediately after the reset operation.

In this case, in normal operation, the voltage variation between the battery modules is 5 times the voltage of the battery modules.
If the voltage of the battery module read out to the differential amplifier circuit via the flying capacitor immediately after the reset operation is less than 50%, it is not a decrease in the voltage of the battery module but a disconnection failure or OFF of the multiplexer. It can be reliably determined that there is a failure. In addition,
The voltage of the battery module may abnormally drop and may drop to 50% or less of the voltage of the battery module read immediately before. In this case, it is not possible to discriminate the disconnection failure or the OFF failure of the multiplexer, but it is possible to determine that it is somehow abnormal. Further, in this case, if the reset period is increased in the next reset operation for the battery module for which the abnormality is determined, the amount of decrease in the storage voltage of the flying capacitor immediately after the reset operation can be increased. It can be done reliably.

According to a sixth aspect of the present invention, in the method of driving the flying capacitor type assembled battery voltage detecting circuit according to the fifth aspect, the turn-on period of the reset circuit is further adjusted based on each module voltage read last time. It has a feature.

That is, the voltage of the battery module is read out to the flying capacitor every fixed short period of time, and there is no possibility that the voltage of the battery module suddenly changes in such a short period under normal conditions. When the voltage is read next time immediately before the reset operation based on the voltage, the reset period is shortened within a range in which the residual voltage after the reset operation can be distinguished from the voltage of the battery module immediately after the reset operation and the residual voltage of the flying capacitor after the reset operation. . By doing so, the amount of discharge of the battery module due to the reset operation can be reduced. Of course, even in this case, if the voltage of the battery module read out to the differential amplifier circuit immediately after the reset operation is determined to be a disconnection failure or an off failure, the reset operation period will be changed in the next reset operation of the voltage of this battery module. Can be sufficiently extended to perform a determination operation for distinguishing between a disconnection failure, an off failure, and an abnormal battery voltage sudden decrease.

According to a seventh aspect of the present invention, there is provided a flying capacitor type assembled battery voltage detecting circuit which comprises a flying capacitor circuit having at least one flying capacitor and N (N> 2) battery modules connected in series to form an assembled battery. A multiplexer that sequentially connects both ends to both ends of the flying capacitor circuit for each of the battery modules and charges the flying capacitor circuit by the voltage of each of the battery modules alternately in polarity every time the voltage of the battery module is read, and a multiplexer. An amplifier circuit and a pair of output-side sampling switches that individually connect a pair of input terminals of the differential amplifier circuit to both ends of the flying capacitor circuit, and the multiplexer has one end at the highest potential of each battery module. Connected to the end, each connection end and the lowest potential end In a driving method of a flying capacitor type assembled battery voltage detection circuit composed of +1 input side sampling switches, an odd number read cycle for sequentially reading the voltage of the odd-numbered battery module to the flying capacitor circuit is performed, and then an even number The read cycle is repeated by performing an even-numbered read cycle for sequentially reading the voltage of the battery module to the flying capacitor circuit.

According to this structure, since the multiplexer is composed of N + 1 input side sampling switches each of which has one end connected to the highest potential end, each connection end and the lowest potential end of each battery module, an odd-numbered sampling switch is provided. The flying capacitor circuit is charged in the opposite direction depending on whether the voltage of the battery module is read or the voltage of the even-numbered battery module is read. Has to be charged in the opposite direction, and the power loss of the battery module is large.

Therefore, in this configuration, the odd-numbered read cycle for continuously reading the voltage of the odd-numbered battery module and the even-numbered read cycle for continuously reading the voltage of the even-numbered battery module are alternately executed.
As a result, even if the multiplexer does not align the charging direction of the flying capacitor circuit in one direction, the power loss of the battery module due to the voltage reading of the battery module can be significantly reduced.

In this configuration, the reset switch for resetting the flying capacitor circuit described above may not be provided, but when it is provided, it is preferable to perform the reset only when the odd-numbered read cycle and the even-numbered read cycle are switched. . By performing this reset operation, it is possible to eliminate the reverse residual charge of the flying capacitor circuit in the voltage reading of the first battery module in the odd-numbered read cycle and the voltage reading of the first battery module in the even-numbered read cycle. Therefore, the power loss of the battery module can be reduced.

According to an eighth aspect of the present invention, in the method for driving the flying capacitor type assembled battery voltage detection circuit according to the seventh aspect, the read voltage of the battery module at the head of the odd read cycle and the even read cycle are further included. Is characterized in that a disconnection failure is determined based on the read voltage of the battery module at the beginning of the above, according to this configuration, the disconnection failure of the read circuit portion of the multiplexer that reads the battery module immediately after the cycle is changed. The presence or absence can be determined.
That is, if this disconnection occurs, the stored voltage in the opposite direction to the original direction is read from the flying capacitor circuit, so that the disconnection failure or the OFF failure can be easily determined.

According to a ninth aspect of the present invention, in the method of driving the flying capacitor type assembled battery voltage detecting circuit according to the eighth aspect, the voltage of the battery module at the beginning of each of the odd read cycle and the even read cycle is further added. It is characterized by having a reset circuit that short-circuits the flying capacitor circuit immediately before reading and attenuates the stored voltage.

According to this structure, it is possible to prevent the reverse voltage from being applied to the differential amplifier circuit at the time of a disconnection failure or an OFF failure, and to reduce the power loss of the voltage of the battery module. .

According to a tenth aspect of the present invention, in the method of driving the flying capacitor type assembled battery voltage detection circuit according to any one of the seventh to ninth aspects, the battery module at the head of the odd number read cycle in each read cycle is further included. , And the leading battery module of the even-numbered read cycle in each read cycle is sequentially shifted.

According to this configuration, the battery modules read out immediately after the cycle are changed in order, so that it is possible to determine the disconnection failure or the OFF failure in the voltage reading paths of all the battery modules. Further, all the battery modules can be consumed evenly.

A flying-capacitor type assembled battery voltage detection circuit according to an eleventh aspect of the present invention includes a flying capacitor circuit having at least one flying capacitor and N (N> 2) battery modules connected in series to form an assembled battery. Both ends are sequentially connected to both ends of the flying capacitor circuit for each battery module, and the flying capacitor circuit is charged with polarity alternately or always with the same polarity each time the voltage of the battery module is read by the voltage of each battery module. Driving a flying capacitor type assembled battery voltage detection circuit including a multiplexer, a differential amplifier circuit, and a pair of output side sampling switches that individually connect a pair of input terminals of the differential amplifier circuit to both ends of the flying capacitor circuit In the method
Each read cycle in which the voltage of each battery module is sequentially read by the flying capacitor circuit has M (M> N) voltage read steps of the battery module, which are performed at predetermined intervals. Reading the voltage of a predetermined number of the battery modules a plurality of times by a plurality of the voltage reading steps in a cycle,
The power storage direction of the flying capacitor circuit by the second voltage reading step of the predetermined battery module read a plurality of times in the read cycle,
It is characterized in that it is performed after the voltage reading step of storing the flying capacitor circuit in the same direction.

That is, in this configuration, the flying capacitor type battery pack voltage detection circuit detects the module voltage M times in the cycle T. However, if the assembled battery has less than M battery modules, the circuit is idle. Therefore, in the voltage reading period of the remaining battery modules after reading the voltage of each battery module, the voltage of a predetermined battery module of the assembled battery is read again to increase the number of measurements.

However, in this configuration, since the multiplexer is composed of N + 1 input side sampling switches each of which has one end connected to the highest potential end, each connection end and the lowest potential end of each battery module, an odd-numbered The flying capacitor circuit is charged in the opposite direction depending on whether the voltage of the battery module is read or the voltage of the even-numbered battery module is read. Has to be charged in the opposite direction, and the power loss of the battery module is large.

Therefore, in this configuration, the battery module to be double read has the same flying capacitor charge direction as the battery module read immediately before.
As a result, it is possible to reduce the power loss of the double read battery module.

In this configuration, the odd-numbered read cycle for continuously reading the voltage of the odd-numbered battery module and the even-numbered read cycle for continuously reading the voltage of the even-numbered battery module are alternately executed. It is preferable. As a result, even if the multiplexer does not align the charging direction of the flying capacitor circuit in one direction, the power loss of the battery module due to the voltage reading of the battery module can be significantly reduced.

According to the structure of claim 12, claim 11
The flying capacitor type assembled battery voltage detection circuit described is further characterized in that a combination of the battery modules read a plurality of times in the one reading cycle is sequentially changed.

However, in the above method, if the battery module to be double read is fixed as described above, the consumption of this battery module is accelerated. Therefore, in this configuration, since the battery modules to be double read are changed in order, it is possible to reduce the variation in the capacity of the battery modules due to the double reading.

According to a thirteenth aspect of the present invention, there is provided a flying capacitor type assembled battery voltage detecting circuit, which comprises a flying capacitor circuit having at least one flying capacitor and N (N> 2) battery modules connected in series to form an assembled battery. A multiplexer that sequentially connects both ends to both ends of the flying capacitor circuit for each of the battery modules and charges the flying capacitor circuit by the voltage of each of the battery modules alternately in polarity every time the voltage of the battery module is read, and a multiplexer. In the driving method of the flying capacitor type assembled battery voltage detection circuit, which includes an amplifier circuit and a pair of output side sampling switches that individually connect a pair of input terminals of the differential amplifier circuit to both ends of the flying capacitor circuit, Change the voltage of the battery module Each of the read cycles for sequentially reading the storage capacitor circuit has M (M> N) voltage reading steps of the battery module performed at predetermined intervals, and the plurality of voltage readings in each of the read cycles are performed. The voltage of a predetermined number of the battery modules is read a plurality of times in a step, and the power storage direction of the flying capacitor circuit in the second voltage reading step of a predetermined battery module that is read a plurality of times in the read cycle is set to the flying direction. It is characterized in that the combination of the battery modules read a plurality of times in one read cycle is sequentially changed after the voltage reading step of storing the capacitor circuit in the reverse direction.

That is, in this configuration, the flying capacitor type battery pack voltage detection circuit detects the module voltage M times in the cycle T. However, if the assembled battery has less than M battery modules, the circuit is idle. Therefore, during the voltage reading period of the remaining battery modules after reading the voltage of each battery module, the voltage of a predetermined battery module of the assembled battery is read again (double reading) to increase the number of measurements.

However, in this configuration, since the multiplexer is composed of N + 1 input side sampling switches each of which has one end connected to the highest potential end, each connection end and the lowest potential end of each battery module, odd-numbered In order to alternately read the voltage of the battery module and the voltage of the even-numbered battery module, if the double reading is performed, only the power loss of the double-read battery module increases.

Therefore, in this configuration, the double read battery modules selected in each read cycle are replaced in order. By doing so, all the battery modules are double-read once each after x times of reading cycles, and it is possible to reduce the voltage variation of the battery modules.

[0040]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the flying capacitor type voltage detection circuit of the present invention will be described in detail below with reference to the following embodiments.

[0041]

[Embodiment 1] (Circuit configuration) A voltage detecting device for an assembled battery to which the present invention is applied will be described with reference to the circuit diagram shown in FIG.

Reference numeral 1 is a battery for storing motive power for a hybrid electric vehicle, 2 is a multiplexer, 3 is a flying capacitor circuit consisting of one flying capacitor C3, 4 is an output side sampling switch circuit, 5 is a differential amplifier circuit, 6 is a reset circuit, which is a multiplexer 2
Reads the signal voltage from the battery 1 to the flying capacitor circuit 3, and the output side sampling switch circuit 4 reads the signal voltage from the flying capacitor circuit 3 to the differential amplifier circuit 5. R20 is a current limiting resistor that limits the discharge current of the flying capacitor circuit 3.

The battery 1 is composed of eight battery modules VB.
10 to VB17 are connected in series.

The multiplexer 2 has a battery 1 at one end.
Highest potential end, lowest potential end and each battery module VB10
Read from the input side sampling switch circuit 21 and the input side sampling switch circuit 21 composed of N + 1 input side sampling switches SSR10 to SSR18, which are individually connected to the connection terminals of VB17 through current limiting resistors R10 to R18. The switching circuit 22 that switches the power transmission direction of the generated signal voltage and sends the signal voltage to the flying capacitor circuit 3.

The switching circuit 22 comprises four switches SW00 to SW03 which are analog switches. The switch (first switch) SW00 is an odd-numbered switch S
SR10, SSR12, SSR14, SSR16, SS
The other end of R18 is individually connected to one end of the flying capacitor C3. The switch (second switch) SW01 is an odd-numbered switch SSR10, SSR12, SSR1.
4, the other ends of SSR16 and SSR18 are individually connected to the other end of the flying capacitor C3. The switch (third switch) SW02 is an even-numbered switch SSR11, S
The other ends of SR13, SSR15, and SSR17 are individually connected to one end of the flying capacitor C3. The switch (fourth switch) SW01 is an even-numbered switch SSR.
The other ends of 11, SSR13, SSR15, and SSR17 are individually connected to the other end of the flying capacitor C3. By turning on the switches SW00 and SW03 at the same time, odd-numbered battery modules VB10, VB12, V
The signal voltages of B14, VB16, and VB18 are read to the flying capacitor C3, and the flying capacitor C3 is charged in one direction. By turning on the switches SW01 and SW02 at the same time, the even-numbered battery modules VB
The signal voltages of 11, VB13, VB15, and VB17 are read to the flying capacitor C3, and the flying capacitor C3 is charged in one direction. That is, the switching circuit 2
2 performs the above operation in synchronization with the input side sampling switches SSR10 to SSR18 of the input side sampling switch circuit 21, and each battery module VB10 to VB17.
The flying capacitor C3 is always charged in the same direction by the signal voltage of.

The output side sampling switch circuit 4 includes a switch SSR as a pair of output side sampling switches.
21 and SSR22, the switch SSR21 connects one end of the flying capacitor C3 to one input end of the differential amplifier circuit 5, and the switch SSR22 connects the other end of the flying capacitor C3 to the other input end of the differential amplifier circuit 5. To do.

The differential amplifier circuit 5 is composed of a normal operational amplifier voltage amplifier circuit, Vref is a reference power source, and sets the potential of the other input terminal (+ input terminal) of the operational amplifier OP to the reference potential through a resistor.

The reset circuit 6 comprises a reset switch SSR26 and a short-circuit current limiting resistance element R20 which are connected in series with each other, and is connected in parallel with the flying capacitor C3. (Description of Basic Operation) The basic operation of the circuit of FIG. 1 will be described below.

Switches SSR10 to SSR1 connected to both ends of the battery modules VB10 to VB17, respectively.
Each pair of switches 8 is sequentially turned on every first half period of a predetermined voltage module read period ΔT that is repeated at a constant cycle, and at the same time, switches SW00 to S of the switching circuit 22 are
The W03 is synchronously turned on as described above, and the voltages (also referred to as module voltages) of the battery modules VB10 to VB17 are sequentially read. In the latter half period of each predetermined cycle ΔT, the switches SSR10 to SSR18 are turned off, and the switches SSR21, S of the output side sampling switch circuit 4 are turned on.
SR22 is turned on to read the stored voltage of the flying capacitor C3 into the differential amplifier circuit 5.

Reset switch SR2 of reset circuit 6
6 is turned on at the final stage of the latter half of the voltage module read period ΔT, and attenuates or erases the storage voltage remaining in the flying capacitor C3. At this time, the proportion of the residual voltage of the flying capacitor C3 can be determined by adjusting the ON period of the reset switch SR26.
In the reset operation, the signal voltage (not including the storage voltage of the battery module) read to the differential amplifier circuit 5 after the reset operation in the state where the disconnection failure or the OFF failure of the multiplexer 2 occurs, and the battery module of the minimum possible voltage It is preferable to increase the residual voltage as much as possible (preferably 50 or more) within a range in which the voltage can be discriminated from the viewpoint of reducing the power loss of the battery module.

(Disconnection Failure or Off Failure Detection Operation 1) By the above operation, the voltages of the battery modules VB10 to VB17 can be sequentially transferred to the differential amplifier circuit 5, and after the reset switch SSR26 is turned on, the next battery module When the voltage is read, if the multiplexer 2 has a disconnection failure or an OFF failure, the signal voltage cannot be read from the battery module to the flying capacitor C3. Therefore, the signal voltage read from the flying capacitor C3 to the differential amplifier circuit 5 is It becomes 0. Therefore, the reset switch SSR2
By determining the magnitude of the voltage of the battery module immediately after 6-ON, disconnection failure or OFF failure of the current path of the multiplexer 2 related to the voltage reading of this battery module can be easily detected.

(Breakdown Failure and Off Failure Detection Operation 2) The voltages of all the battery modules VB10 to VB17 are set to VB10.
From the differential amplifier circuit 5 in order to read the voltage of VB17, and then a reset switch (also referred to as SW1 in the drawing) SSR2
When 6 is turned on, immediately after that, the flying capacitor C3
The battery module connected to is the flying capacitor C
Discharging progresses due to the charging of No. 3. This problem becomes particularly serious if only certain battery modules are always selected immediately after this reset operation. Further, in this case, it is possible to detect only the disconnection failure and the OFF failure of the current path connected to this specific battery module.

Therefore, the battery modules selected immediately after the reset operation are sequentially changed for each read cycle. As a result, it is possible to reduce the capacity variation between the battery modules.

(Modification) In the above example, all the battery modules are read once in one read cycle period.
The read order of the battery modules within each read cycle was changed, but instead of this, the number of reads that exceeded the number of battery modules was performed within one read cycle period, and some battery modules were read twice within one read cycle period. You may read it. In this case, the reading order of the battery modules is the same. In this way, the battery modules read immediately after the reset operation are displaced by the number of battery modules read an extra number of times, so that eventually all the battery modules can be evenly arranged immediately after the reset operation. The number of battery modules read out an extra number of times is preferably set to 1, but need not be 1 if all the battery modules are arranged immediately after the reset operation as the cycle is repeated.

Further, only the battery module read for the second time, which corresponds to the battery module for reading this extra number of times, may be read for each read cycle.

(Reset Operation) The previous read voltage of the voltage of the battery module read immediately after the reset operation is stored, and the reset period is set so that a voltage smaller than the stored value by a predetermined value remains in the flying capacitor C3. If so, useless power loss of the battery module can be reduced.

(Modification) By changing the number of reset operations or the ON period according to the voltage of the battery modules, it is possible to reduce the voltage variation among the battery modules VB10 to VB17. That is, the ON period of the reset operation performed immediately before the next read of the battery module with a large previous read voltage value is lengthened, or the average number of reset operations performed immediately before the battery module with a large previous read voltage value. Is increased, it is possible to promote the decrease in the storage voltage of the battery module having a large previous read voltage value, and it is possible to reduce the voltage variation.

(Modification) In the above embodiment, the reset switch SSR26 is turned on when the output side sampling switch circuit 4 outputs the output side sampling switches SSR21, SS.
I did it after turning off R22, but the reset switch SS
The R26 may be turned on in the latter half of the on period of the output side sampling switches SSR21 and SSR22 of the output side sampling switch circuit 4. If you do this,
Since the electric charge remaining in the parasitic capacitance of the signal line connecting the output side sampling switches SSR21 and SSR22 and the operational amplifier OP can also be canceled, it is possible to reduce the deterioration of the reading accuracy due to the residual electric charge.

[0059]

Second Embodiment Another embodiment of the present invention will be described below with reference to FIG.

In this embodiment, the consumption of the battery modules VB10 to VB17 by the flying capacitor C3 is reduced by using a multiplexer in which the switching circuit 22 of the multiplexer 2 shown in FIG. 1 is omitted.

In the conventional circuit of this type, the switches SSR10 to SSR1 of the input side sampling switch circuit 21 are arranged.
8 was sequentially turned on in the order of being adjacent to each other. For this reason,
The battery modules VB10 to VB17 always discharge the residual voltage stored in the opposite direction and then store their own voltage in the flying capacitor C3.
The consumption of 0 to VB17 was great.

Therefore, in this embodiment, the voltage reading cycle of each battery module is carried out as follows to reduce the consumption of the battery module. First, an odd-numbered read cycle for sequentially reading all the voltages of the odd-numbered battery modules is performed, and then an even-numbered read cycle for sequentially reading all the voltages of the even-numbered battery modules is performed. By doing so, the residual voltage in the reverse direction of the flying capacitor C3 causes the capacity of the battery module to be significantly consumed only in the first battery module in each of the odd read cycle and the even read cycle. Therefore, consumption of other battery modules can be reduced.

(Modification) Also in this embodiment, the reset switch SSR26 (SW1) is turned on after the switches SSR21 and SSR22 are turned on immediately before the voltage reading of the first battery module in the odd read cycle and the even read cycle, respectively. As a result, it is possible to reduce the consumption of the battery module immediately after.

(Modification) However, this embodiment 2 described above
Also in the above, if the battery modules to be read first in each of the odd-numbered read cycle and the even-numbered read cycle are always fixed in part, each battery module VB1
The voltage variation between 0 and VB17 increases.

Therefore, the battery modules read first in the odd number read cycle and the even number read cycle are sequentially replaced. As a result, it is possible to substantially equalize the consumption of the battery modules VB10 to VB17 due to the charge transfer to the flying capacitor C3.

Of course, also in this case, the reset switch SSR2 is set before the voltage of the battery module is first read in each of the odd read cycle and the even read cycle.
It is preferable to turn on 6 to reduce the carry-out of charges from the battery module.

(Modification) In the above embodiment, the disconnection failure or the OFF failure (for example, disconnection or failure in which the switch of the multiplexer 2 does not turn on) is caused by the battery module at the beginning of each of the odd read cycle and the even read cycle. Alternatively, the reset operation may be performed by the reset switch SSR26 at the end of the odd-numbered read cycle and the even-numbered read cycle, and may be performed based on the voltage of the battery module read immediately thereafter.

(Modification) In the second embodiment, each odd-numbered read cycle is a cycle in which the voltage of the odd-numbered battery module is read once, and in the even-numbered read cycle, the voltage of the even-numbered battery module is read once each. The number of battery module readings included in one odd-numbered read cycle and one even-numbered read cycle can be set arbitrarily.

For example, in an odd-numbered read cycle of the read cycle, voltages of a predetermined combination of odd-numbered battery modules are sequentially read, and then voltages of a predetermined combination of even-numbered battery modules are sequentially read.

Each odd-numbered read cycle can include an odd-numbered battery module that is read only once and an odd-numbered battery module that is read multiple times, and similarly, the even-numbered battery module is read only once. An even-numbered battery module that is read multiple times, and an even-numbered battery module that is additionally read in addition to all the even-numbered battery modules. be able to. However, each battery module VB10-V
The average probability that B17 immediately follows the odd-numbered read cycle or the even-numbered read cycle and the voltage read frequency of each battery module are equalized as a whole, so that the consumption of each battery module VB10 to VB17 can be equalized.

Alternatively, each odd read cycle can include a portion of an odd-numbered battery module, as well as a portion of an even-numbered battery module. The next odd read cycle may include the balance of the odd-numbered battery modules, and likewise may include the balance of the even-numbered battery modules. That is, the voltage reading of the odd-numbered battery module is completed by a plurality of odd-numbered read cycles, and the voltage reading of the even-numbered battery module is completed by a plurality of even-numbered read cycles. However, however, the voltage module VB1
The average probability that 0 to VB17 immediately follows an odd number read cycle or an even number read cycle and the voltage reading frequency of each battery module are equalized as a whole, and thus the consumption of each battery module VB10 to VB17 can be equalized. .

In this example, in particular, the total number of read times of the battery modules in one odd read cycle or one even read cycle of the flying capacitor type assembled battery voltage detection circuit and the actual number of battery modules of the battery 1 are shown. Even if there is a mismatch due to a circuit or battery design change, there is an advantage that the voltage of each battery module can be read out with equal frequency and the consumption of each battery module can be equalized.

(Modification) In the above modification, the voltage of each battery module as a whole is equalized even if the number of battery modules of the battery 1 does not match the number of times of battery module reading performed in one read cycle. And the consumption of the battery modules in this read was averaged, but a complete odd read cycle to read the voltage of all odd-numbered battery modules,
Performing a complete even read cycle to read the voltage of all even battery modules first, and then additionally reading a predetermined combination of odd battery modules or some of the even battery modules. A partial read cycle can be performed. Even in this case, at least the battery modules read immediately after changing the reading of the odd-numbered battery modules and the reading of the even-numbered battery modules,
Changed in order, each battery module VB10 ~ VB17
The degree of consumption is averaged. In this case, the direction in which the battery module read in this additional partial read cycle charges the flying capacitor C3 is the same as the flying capacitor charging direction in the immediately preceding odd-numbered (or even-numbered) read cycle. However, it is important in reducing the consumption of the battery module.

(Disruption Failure or Off Failure Determination) The disconnection failure or off failure determination in this embodiment can be performed based on the voltage of the battery module immediately after the odd read cycle and the even read cycle. Further, when the reset operation is performed immediately before the voltage reading of the battery module performed immediately after the odd read cycle and the even read cycle, the disconnection failure or the off failure occurs based on the voltage of the battery module performed immediately after the reset operation. Can be detected.

That is, if the voltage of the battery module immediately after the above is a reverse voltage or the voltage of the flying capacitor C3 after reset is less than a predetermined value,
It can be determined that the voltage is not normally read from the battery module immediately after the above.

[0076]

Third Embodiment Another embodiment of the present invention will be described below with reference to FIG.

This embodiment is different from the first embodiment shown in FIG. 1 in that the flying capacitor circuit 3 is composed of two flying capacitors C3 and C3 'connected in series, and the reset circuit 6 is the same as the reset circuit 6 of FIG. The first reset circuit 6x and the second reset circuit 6y having the configuration
The reset circuit 6x is connected in parallel to the flying capacitor C3, and the second reset circuit 6y is connected to the flying capacitor C3.
3'is connected in parallel, and the connection points of the flying capacitors C3 and C3 'having substantially the same capacitance are connected to the reference power supply Vref through the switch SSR23. The first reset circuit 6x includes a reset switch SSR26a (SW2) and a resistance element R26a, and the second reset circuit 6y includes a reset switch SSR26b (SW3) and a resistance element R.
26b.

The operation of this circuit will be described. In this circuit, the voltage ΔV of the battery module is controlled by the multiplexer 2.
s is stored in the flying capacitors C3 and C3 'in half. After that, the switches SSR21, SSR22, S
SRW23 is turned on, flying capacitors C3, C
The signal voltage 3 ′ is read out to the differential amplifier circuit 5. With this configuration, a potential higher by 0.5ΔVs and a potential lower by 0.5ΔVs than the reference potential of the reference power source Vref are applied to the pair of input ends of the differential amplifier circuit 5. The influence of parasitic capacitance is reduced, and the differential amplifier circuit 5 is accurately
Of the reference potential source Vref can be made to swing to both sides of the reference voltage of the reference potential source Vref as an intermediate voltage value.

In the circuit of FIG. 3 as well, similar to the first and second embodiments, it is possible to average the consumption of each battery module and determine the disconnection failure and the off failure.

[0080]

Fourth Embodiment Another embodiment of the present invention will be described below with reference to FIG.

In this embodiment, in FIG. 3, the reset circuit 6 is constituted by the reset switch SSR26 and the current limiting resistor R20 shown in FIG. 1, and the output side sampling switch circuit 4'is made up of three output side sampling switches SSR2.
1, SSR22, SSR23, and differential amplifier circuits 5a and 5b equivalent to the differential amplifier circuit 5 shown in FIG. 1 are provided in the differential amplifier circuit 5 '.

The differential amplifier circuit 5a detects the storage voltage of the flying capacitor C3 through the output side sampling switches SSR21 and SSR22, and the differential amplifier circuit 5b.
Are output side sampling switches SSR23 and SSR2.
The storage voltage of the flying capacitor C3 'is detected through 2.

According to this circuit configuration, the battery module V
The voltages of B10, VB13, VB14, VB17 are detected by the differential amplifier circuit 5a after charging the flying capacitor C3 in the same direction, and the battery modules VB11, VB are detected.
The voltages of 12, VB15 and VB16 are detected by the differential amplifier circuit 5b after charging the flying capacitor C3 ′ in the same direction. According to this circuit. The charging directions of the flying capacitors C3 and C3 ′ can be aligned without using a switching circuit. Also in this circuit, by adopting the same method as that of the first embodiment, it is possible to reduce the disconnection failure, the off failure, and the consumption of the battery module.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a flying capacitor type voltage detection circuit according to a first embodiment.

FIG. 2 is a circuit diagram showing a flying capacitor type voltage detection circuit according to a second embodiment. FIG. 6 is a circuit diagram showing a modification of the first embodiment.

FIG. 3 is a circuit diagram showing a flying capacitor type voltage detection circuit according to a third embodiment.

FIG. 4 is a circuit diagram showing a flying capacitor type voltage detection circuit according to a fourth embodiment.

[Explanation of symbols]

1 battery 2 multiplexer 3 Flying capacitor circuit 4 Output side sampling switch circuit 5 Differential amplifier circuit

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2G016 CA03 CB01 CC01 CC04 CC12                       CC14 CC19 CD10 CD14                 2G035 AA12 AA20 AB03 AC16 AD11                       AD17 AD20 AD44 AD46                 5G003 BA03 CA11 EA09                 5H030 AA06 AS08 FF44

Claims (13)

[Claims] 1. A flying capacitor circuit having at least one flying capacitor, and N (N> 2) battery modules connected in series to form an assembled battery, and both ends of each of the battery modules are connected to the flying capacitor circuit. A multiplexer that is sequentially connected to both ends to charge the flying capacitor circuit in the same direction by the voltage of each battery module, a differential amplifier circuit, and a pair of input terminals of the differential amplifier circuit of the flying capacitor circuit. In a flying capacitor type assembled battery voltage detection circuit comprising a pair of output side sampling switches individually connected to both ends, after reading the stored voltage of the flying capacitor circuit to the differential amplifier circuit through the output side sampling switch, And the following battery module The shorting flying capacitor circuit flying capacitor type battery pack voltage detection circuit, characterized in that it comprises a reset circuit for attenuating the power storage voltage before reading the voltage to the flying capacitor circuit through the multiplexer. 2. The flying capacitor type assembled battery voltage detection circuit according to claim 1, wherein the multiplexer includes N + 1 pieces of which one end is connected to the highest potential end, each connection end and the lowest potential end of each battery module. An input side sampling switch, a first switch for individually connecting the other ends of the odd numbered input side sampling switches to one end of the flying capacitor circuit, and a respective other end of the odd numbered input side sampling switch for the flying capacitor A second switch individually connected to the other end of the circuit, a third switch individually connecting each other end of the even-numbered input side sampling switches to one end of the flying capacitor circuit, and an even-numbered input side sampling switch A fourth switch in which each other end is individually connected to the other end of the flying capacitor circuit. Has a switch, the flying capacitor type battery pack voltage detection circuit and having a current switching circuit for charging the flying capacitor circuit always in the same direction by charge transfer from each of the cell modules. 3. The driving method of a flying capacitor type assembled battery voltage detection circuit according to claim 1, wherein a disconnection failure is determined based on the voltage of the battery module read immediately after the short circuit discharge operation of the reset circuit. A method for driving a flying capacitor type assembled battery voltage detection circuit, which is characterized in that. 4. The driving method of the flying capacitor type assembled battery voltage detection circuit according to claim 1, wherein the voltage of the battery module is read into the flying capacitor circuit through the multiplexer, and the storage voltage of the flying capacitor circuit is output to the output side. After a certain number of read cycles for outputting to the differential amplifier circuit through a sampling switch and turning off the output side sampling switch to sequentially read the voltage of each battery module, short circuit discharge of the flying capacitor circuit by the reset circuit A method of driving a flying capacitor type assembled battery voltage detection circuit, wherein the voltage of the battery module read after the short-circuiting operation is sequentially changed by performing the operation. 5. The driving method of a flying capacitor type assembled battery voltage detecting circuit according to claim 4, wherein the flying capacitor is partially discharged (discharging amount is less than 50%) by the short circuit discharging operation of the flying capacitor circuit by the reset circuit. A method for driving a flying capacitor type assembled battery voltage detection circuit, characterized by: 6. The method for driving a flying capacitor type assembled battery voltage detection circuit according to claim 5, wherein the turn-on period of the reset circuit is adjusted based on each module voltage read last time. Battery pack voltage detection circuit. 7. A flying capacitor circuit having at least one flying capacitor, and N (N> 2) battery modules connected in series to form an assembled battery. A multiplexer that is sequentially connected to both ends and that charges the flying capacitor circuit by the polarity of the voltage of each battery module alternately for each voltage reading of the battery module, a differential amplifier circuit, and a pair of inputs of the differential amplifier circuit. A pair of output side sampling switches that individually connect terminals to both ends of the flying capacitor circuit; and the multiplexer has one end connected to the highest potential end, each connection end and the lowest potential end of each battery module. N
In a driving method of a flying capacitor type assembled battery voltage detection circuit composed of +1 input side sampling switches, an odd number read cycle for sequentially reading the voltage of an odd-numbered battery module to the flying capacitor circuit is performed, and then an even number A driving method for a flying capacitor type assembled battery voltage detection circuit, characterized in that an even-numbered read cycle for sequentially reading the voltage of the battery module to the flying capacitor circuit is repeated to repeat a read cycle. 8. The driving method for a flying capacitor type assembled battery voltage detection circuit according to claim 7, wherein the read voltage of the battery module at the head of the odd read cycle and the battery at the head of the even read cycle. A driving method of a flying capacitor type assembled battery voltage detection circuit, characterized in that a disconnection failure is determined based on a read voltage of a module. 9. The driving method of a flying capacitor type assembled battery voltage detection circuit according to claim 8, wherein the flying capacitor circuit is provided immediately before reading the voltage of the battery module at the beginning of each of the odd read cycle and the even read cycle. A flying capacitor type assembled battery voltage detection circuit having a reset circuit that short-circuits and attenuates the stored voltage. 10. The driving method of the flying capacitor type assembled battery voltage detection circuit according to claim 7, wherein the leading battery module of the odd read cycle in each read cycle and the read cycle in each read cycle. A driving method of a flying capacitor type assembled battery voltage detection circuit, wherein the first battery module of the even-numbered read cycle is sequentially shifted. 11. A flying capacitor circuit having at least one flying capacitor, and N (N> 2) battery modules connected in series to form an assembled battery, and both ends of each of the battery modules are connected to the flying capacitor circuit. A multiplexer that is sequentially connected to both ends and charges the flying capacitor circuit alternately or constantly with the same polarity for each voltage reading of the battery module by the voltage of each battery module; a differential amplifier circuit; And a pair of output side sampling switches for individually connecting a pair of input terminals of the circuit to both ends of the flying capacitor circuit, and a method for driving a flying capacitor type assembled battery voltage detection circuit, comprising: Sequential reading with a capacitor circuit Each read cycle includes M (M> N) voltage reading steps of the battery module performed at predetermined intervals, and a predetermined number of the voltage reading steps are performed by the plurality of voltage reading steps in each read cycle. The voltage of the battery module is read a plurality of times, and the storage direction of the flying capacitor circuit by the second voltage reading step of the predetermined battery module that is read a plurality of times in the read cycle,
A method of driving a flying capacitor type assembled battery voltage detection circuit, which is performed after the voltage reading step of storing the flying capacitor circuit in the same direction. 12. The flying capacitor type assembled battery voltage detecting circuit according to claim 11, wherein a combination of the battery modules read a plurality of times in the one reading cycle is sequentially changed. Driving method of voltage detection circuit. 13. A flying capacitor circuit having at least one flying capacitor, and N (N> 2) battery modules connected in series to form an assembled battery, and both ends of each of the battery modules are connected to the flying capacitor circuit. A multiplexer that is sequentially connected to both ends and that charges the flying capacitor circuit by the polarity of the voltage of each battery module alternately for each voltage reading of the battery module, a differential amplifier circuit, and a pair of inputs of the differential amplifier circuit. In a method of driving a flying capacitor type assembled battery voltage detection circuit, which comprises a pair of output side sampling switches for individually connecting terminals to both ends of the flying capacitor circuit, the voltage of each battery module is sequentially applied to the flying capacitor circuit. Each time the read service is read Clu has M (M> N) voltage reading steps of the battery module performed every predetermined period, and the voltage of a predetermined number of the battery modules is read by the plurality of voltage reading steps in each read cycle. Is read a plurality of times, the storage direction of the flying capacitor circuit by the second voltage reading step of the predetermined battery module read a plurality of times in the read cycle,
A flying capacitor type assembled battery voltage, which is performed after the voltage reading step of storing the flying capacitor circuit in a reverse direction, and sequentially changes a combination of the battery modules read a plurality of times in one read cycle. Driving method of detection circuit.