JP2008175597A - Voltage detection device for battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect a voltage of each single battery constituting a battery pack with a simple circuit constitution. <P>SOLUTION: In the voltage detection device for the battery pack with capacitors 2a, 2b, 2c, 2d connected in parallel to each single battery in the battery pack 1 formed by connecting in series a plurality of single batteries 1a, 1b, 1c, 1d, after charging the plurality of capacitors by each single battery, each holding voltage of the charged capacitors is input into input terminals 4a, 4b of a voltage detection element SD. In the plurality of capacitors grouped into a plurality of groups so that adjacent capacitors in the arrangement order by the potential do not belong to the same group, an operation wherein each wire corresponding to capacitors belonging to the same group is connected to the same input terminal, and the low potential side of each capacitor is connected to the negative pole side of the whole battery pack, and the high potential side is connected to the input terminal is repeated from the low potential side to the high potential side sequentially relative to the plurality of capacitors. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention provides a capacitor connected in parallel to each unit cell in an assembled battery in which a plurality of unit cells are connected in series, and in the middle of the wiring between the positive electrode side of each unit cell and each of the capacitors. Corresponding to each of the plurality of battery-side switch devices arranged and turned on and off of the wiring and the plurality of capacitors connected in series, the input of the voltage detection element from the high potential side of each of the capacitors A plurality of capacitor-side switch devices that are arranged in the middle of the voltage detection wiring toward the terminal and turn on and off the power supply of the wiring; and a ground connection for connecting the voltage detection wiring to the negative electrode side of the entire assembled battery A plurality of ground connection switch devices arranged in the middle of the wiring to turn on and off the wiring; the battery side switch device; the capacitor side switch device; A switch control device for controlling opening and closing of the switch device for round connection, and the switch control device opens the battery switch device after charging the plurality of capacitors with the battery switch device closed. The assembled battery voltage detecting device is configured to open and close the capacitor-side switch device and the ground connection switch device so as to input the holding voltage of each of the charged capacitors to the input terminal after switching. About.

Such an assembled battery voltage detection apparatus is an apparatus for individually detecting the battery voltage of each unit cell in order to monitor the operating state of each unit cell constituting the assembled battery.
As such an apparatus, conventionally, for example, a circuit configuration as described in Patent Document 1 below has been proposed.
As shown in FIG. 4, the voltage detection circuit described in Patent Document 1 below is described by exemplifying a case where four assembled cells 100a, 100b, 100c, and 100d are connected in series as the assembled battery 100. In addition, four capacitors 101, 102, 103, and 104 are connected in parallel with each of the unit cells 100a, 100b, 100c, and 100d.
Since the four unit cells 100a, 100b, 100c, and 100d are connected in series, the four capacitors 101, 102, 103, and 104 are also connected in series.
Switches 105, 106, 107, 108 are arranged in the middle of the wiring between the positive side of each of the cells 100 a, 100 b, 100 c, 100 d and the capacitors 101, 102, 103, 104, and are connected in series. Corresponding to each of the four capacitors 101, 102, 103, 104, a switch is placed in the middle of the voltage detection wiring from the high potential side of each of the capacitors 101, 102, 103 to the input terminal of the voltage detection element. 109, 110, 111 are arranged.
Further, switches 112, 113, 114 are arranged in the middle of the wiring for connecting the voltage detection wiring to the negative electrode side of the entire assembled battery 100 (that is, the negative electrode side of the unit cell 100 d located on the lowest potential side). Yes. The negative electrode side of the assembled battery 100 as a whole corresponds to the ground, and is also connected to the ground terminal of the voltage detection element.
In the circuit of FIG. 4, there is no problem even if the high potential side of the capacitor 104 is directly connected to the voltage detection element, so that the switch is omitted.
Further, as the voltage detecting element, a microprocessor 115 incorporating an A / D converter is illustrated.

In the circuit of FIG. 4, the microprocessor 115 performs opening / closing control of each switch.
The procedure for voltage detection of each unit cell 100a, 100b, 100c, 100d will be schematically described. When a sequence for voltage detection is started from a state in which all switches are open (off state). First, the switches 105, 106, 107, and 108 are closed (ON state).
As a result, the capacitors 101, 102, 103, and 104 are charged by the battery voltages of the corresponding single cells 100a, 100b, 100c, and 100d.
When the switches 105, 106, 107, 108 are opened after the completion of the charging, the capacitors 101, 102, 103, 104 hold the voltage corresponding to the battery voltage.

At this time, the holding voltage of the capacitor 104 holding the battery voltage of the unit cell 100d is input to the input terminal “A / D1”, and the battery voltage of the unit cell 100d can be detected.
Next, the switch 114 is switched to the closed state so that the low potential side of the capacitor 103 is connected to the ground and the capacitor 104 is discharged.
When the switch 111 is closed in this state, the holding voltage of the capacitor 103 holding the battery voltage of the unit cell 100c is input to the input terminal “A / D2”, and the battery voltage of the unit cell 100c can be detected.
Thereafter, similarly, the opening and closing of the switches 109, 110, 112, and 113 are controlled, and the holding voltages of the capacitors 101 and 102 are sequentially input to the input terminals “A / D3” and “A / D4”.

By detecting the voltage of each of the single cells 100a, 100b, 100c, and 100d in this manner, the microprocessor 115 detects the battery voltage of each of the single cells 100a, 100b, 100c, and 100d by sequentially shifting the detection timing. Since the detected voltage value itself is output from each of the single cells 100a, 100b, 100c, and 100d at the same time, an error due to a shift in detection time does not occur.
Furthermore, since the voltage applied to the input terminal of the microprocessor 115 is an individual voltage of each of the single cells 100a, 100b, 100c, and 100d, the voltage applied to the input terminal is low even if the number of single cells is large. The withstand voltage characteristics of the input terminals do not need to be considered so much and the voltage detection resolution can be increased.
JP 2001-56350 A

However, the above conventional configuration requires as many input terminals for the voltage detection elements as the number of single cells, and therefore, in particular, when a large number of single cells are provided, a large number of input terminals are required. The configuration becomes complicated.
Along with this, the number of necessary switches also increases.
The present invention has been made in view of such circumstances, and an object of the present invention is to enable voltage detection of a single cell constituting an assembled battery with a simple circuit configuration.

  1st invention of this application is the capacitor | condenser connected in parallel with respect to each cell in the assembled battery which connected the some cell in series, Between the positive electrode side of each said cell, and each of the said capacitor | condenser Corresponding to each of the plurality of battery-side switch devices arranged in the middle of the wiring and turning on and off the wiring, and the plurality of capacitors connected in series, the voltage from each high-potential side of the capacitor A plurality of capacitor-side switch devices arranged in the middle of the voltage detection wiring toward the input terminal of the detection element to turn on and off the wiring, and the voltage detection wiring connected to the negative electrode side of the entire assembled battery A plurality of ground connection switch devices arranged in the middle of the ground connection wiring to turn on and off the wiring, the battery side switch device, and the capacitor side switch And a switch control device that controls opening and closing of the ground connection switch device, and the switch control device charges the plurality of capacitors after charging the plurality of capacitors with the battery side switch device closed. For an assembled battery configured to switch to an open state, and then to control opening and closing of the capacitor side switch device and the ground connection switch device so as to input a holding voltage of each charged capacitor to the input terminal The capacitor-side switch in the voltage detection wiring for a plurality of the capacitors that are grouped into a plurality of groups so that adjacent capacitors do not belong to the same group in the order of arrangement in terms of potential. In the portion closer to the input terminal than the device, the same said Wirings corresponding to the capacitors belonging to the loop are combined into one and connected to the same input terminal, and the ground connection wiring is the capacitor-side switch in the voltage detection wiring for each group. The switch control device connects the low potential side of each of the capacitors to the negative electrode side of the entire assembled battery and connects the high potential side to the input terminal. The capacitor side switch device and the ground connection switch device are controlled to be opened and closed so that the operation is sequentially repeated for the plurality of capacitors from the low potential side to the high potential side.

That is, for detecting the battery voltage of each unit cell in an assembled battery configured by connecting a plurality of unit cells in series, a capacitor is connected in parallel to each unit cell, and each unit cell and each capacitor The battery-side switch device that turns on and off the wiring between them is closed (ON state), the capacitor is charged with the voltage of each unit cell, and then the battery-side switch device is returned to the open state (OFF state). By detecting the voltage, the battery voltage of each unit cell is detected.
For detecting the voltage of each capacitor, the number of voltage detection element input terminals corresponding to the number of each capacitor is not provided, but the plurality of capacitors are grouped so that the voltage detection element for each group is detected. The input terminal is provided.

As a method of grouping the plurality of capacitors, the plurality of capacitors are grouped so that adjacent capacitors do not belong to the same group in the arrangement order of potentials.
The plurality of capacitors are respectively connected in parallel with the single cells, but since the single cells are connected in series, the plurality of capacitors are also connected in series.
In the plurality of capacitors grouped in this way, as described above, wiring from capacitors belonging to the same group is connected to the same input terminal.
Further, the voltage detection wiring from the high potential side of each capacitor to the input terminal is individually turned on and off for each capacitor by the capacitor side switch device, and the position on the input terminal side relative to the capacitor side switch device. The wirings corresponding to the capacitors of the same group are combined and connected together.
The ground connection wiring for connecting the voltage detection wiring to the negative electrode side of the entire assembled battery (for convenience, this position is referred to as “ground”) is connected to a position in a state of being grouped together in the same group, It will be provided in the above group unit.

In this state of electrical wiring, the switch control device performs control so that the voltage of each capacitor is individually detected from the state in which each capacitor is charged by the battery voltage of the corresponding unit cell.
That is, the operation of connecting the low potential side of each of the plurality of capacitors connected in series to the ground and connecting the high potential side to the input terminal is sequentially repeated from the low potential side to the high potential side.

Specifically, for a certain capacitor, both the capacitor-side switch device connected to the low-potential side of the capacitor and the ground connection switch device connected to the capacitor-side switch device are closed (on state), thereby bringing the capacitor to the ground side. The capacitor side switch device connected to the high potential side of the capacitor is closed (ON state), and the ground connection switch device connected to the capacitor side switch device is opened (OFF state). Connect to the input terminal (voltage detection element).
When the low potential side of a capacitor is connected to ground, the capacitor on the low potential side of that capacitor will be discharged, but the voltage of the discharged capacitor has been detected so that detection has already been completed. The voltage detection order is set.

  Since adjacent capacitors are grouped so that they do not belong to the same group in the order of potential, the connection to the ground side and the connection to the input terminal (voltage detection element) are independent for each capacitor. The above control is possible.

Further, according to a second invention of the present application, in addition to the configuration of the first invention, the plurality of groups include an odd-numbered group and an even-numbered group in the potential order. It is divided into two groups.
That is, as a method of grouping so that adjacent capacitors do not belong to the same group in the arrangement order by potential, for example, the number of groups is set to 3 or more, and each capacitor is assigned to each group in the arrangement order by potential. Although a method of allocating in order is possible, grouping into an odd-numbered capacitor and an even-numbered capacitor makes it possible to reduce the number of groups to two.

According to the first aspect of the present invention, the capacitors that hold the battery voltage of each unit cell are divided into a plurality of groups, and the input terminal of the voltage detection element and the ground connection switch device are provided for each group. Therefore, compared with the case where each capacitor is provided, the voltage detection of the unit cell constituting the assembled battery can be performed with a simple circuit configuration.
According to the second aspect of the invention, the number of groups is set to the minimum two groups, so that the voltage detection of each unit cell can be performed with a very simple circuit configuration.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an assembled battery voltage detection device according to the present invention will be described below with reference to the drawings.
FIG. 1 shows a circuit configuration in a state where the assembled battery 1 and the assembled battery voltage detection device VS are connected in a circuit.
The assembled battery 1 is configured by connecting a plurality of unit cells 1a, 1b, 1c, and 1d in series. In this embodiment, for convenience of explanation, four unit cells 1a, 1b, 1c, and 1d are provided. A case where they are connected in series will be described as an example. However, in practice, an assembled battery is configured by connecting a larger number of single cells in series. The unit cells 1a, 1b, 1c, and 1d are lithium ion batteries that are examples of secondary batteries. However, the present invention is not limited to such secondary batteries but can be applied to various assembled batteries.

The assembled battery voltage detection device VS has capacitors 2a, 2b, 2c, and 2d connected in parallel to the cells 1a, 1b, 1c, and 1d, and the battery voltages of the cells 1a, 1b, 1c, and 1d. In this case, the capacitors 2a, 2b, 2c, and 2d corresponding thereto are charged, and the voltages of the capacitors 2a, 2b, 2c, and 2d that have been charged are sequentially detected.
The single cells 1a, 1b, 1c, and 1d are turned on and off at intermediate points in the wiring between the positive electrodes of the single cells 1a, 1b, 1c, and 1d and the capacitors 2a, 2b, 2c, and 2d. , 1d, a plurality of (four) battery side switch devices 3a, 3b, 3c, 3d for switching whether to charge the corresponding capacitors 2a, 2b, 2c, 2d are arranged.
In the present embodiment, the battery side switch devices 3a, 3b, 3c, 3d are constituted by analog switches.

The voltages of the capacitors 2a, 2b, 2c, and 2d are inputted to and detected by the circuit elements for detecting the voltages. In the present embodiment, the microprocessor 4 is provided as the voltage detecting element SD. Yes.
The microprocessor 4 of the present embodiment is a so-called one-chip microcomputer that also incorporates peripheral circuits such as a memory and an A / D converter.

The voltage detection input terminals 4a and 4b in the microprocessor 4 are two input terminals indicated as "A / D1" and "A / D2" in FIG. / D converter input terminal.
A plurality of (four) capacitors that turn on and off the wiring SC at a midpoint of the voltage detection wiring SC from the high potential side of each capacitor 2a, 2b, 2c, and 2d to the input terminals 4a and 4b. The side switch devices 5a, 5b, 5c, 5d are arranged corresponding to the plurality of (four) capacitors 2a, 2b, 2c, 2d connected in series.
In the present embodiment, the capacitor side switch devices 5a, 5b, 5c and 5d are also constituted by analog switches.

There are four voltage detection lines SC at the time of coming out of the capacitors 2a, 2b, 2c, and 2d. However, since there are two input terminals 4a and 4b, a plurality of lines SC are combined into one. Input to the input terminals 4a and 4b.
This wiring is organized by grouping the capacitors 2a, 2b, 2c, 2d constituting the assembled battery 1 into a plurality of groups, and for each group, the capacitors 2a, 2b, 2c, 2d belonging to the same group. Corresponding wiring SC is connected to one wiring, which is connected to input terminals 4a and 4b. That is, the wires corresponding to the capacitors 2a, 2b, 2c and 2d belonging to the same group are combined into one and connected to the same input terminals 4a and 4b. Specifically, the capacitors 2a and 2c A group is connected to the input terminal 4a, and a group of the capacitor 2b and the capacitor 2d is connected to the input terminal 4b.
The position where the plurality of wirings SC are combined into one wiring is a portion of the voltage detection wiring SC that is closer to the input terminals 4a and 4b than the capacitor side switching devices 5a, 5b, 5c, and 5d. It may be connected in the immediate vicinity of 4a and 4b.

The method of grouping the plurality of capacitors 2a, 2b, 2c, 2d is the same for the adjacent capacitors 2a, 2b, 2c, 2d in the arrangement order of the potentials of the capacitors 2a, 2b, 2c, 2d connected in series. Group so that it does not belong to a group.
In the present embodiment, the groups are divided into two groups, that is, an odd-numbered group and an even-numbered group in the order of arrangement in terms of potential so that the number of groups is minimized.

The voltage detection wiring SC having the wiring configuration as described above is connected to the negative electrode side of the entire assembled battery 1, that is, the negative electrode side of the cell 1d on the lowest potential side. The wiring GC is connected.
Hereinafter, the negative electrode side of the entire assembled battery 1 is referred to as “ground” for convenience.
The ground connection wiring GC is connected to each of the wirings grouped in units of the group, and the capacitor side switch devices 5a, 5b, 5c, It is in a relationship of being connected to a portion closer to the input terminals 4a and 4b than 5d. Accordingly, there are two wirings GC for the even-ordered group and the wiring GC for the odd-numbered group.
In the middle of the ground connection wiring GC, ground connection switch devices 6a and 6b for turning on and off the wiring are provided. The ground connection switch devices 6a and 6b are also constituted by analog switches.
This ground is also connected to the ground terminal of the microprocessor 4, and the A / D converter built in the microprocessor 4 converts the voltage between the ground terminal and the input terminals 4a and 4b into digital data.

Open / close control of the battery side switch devices 3a, 3b, 3c, 3d, the capacitor side switch devices 5a, 5b, 5c, 5d and the ground connection switch devices 6a, 6b is executed by the microprocessor 4, and the microprocessor 4 performs switch control. It also functions as the device CC.
Hereinafter, the open / close control for the battery side switch devices 3a, 3b, 3c, 3d, the capacitor side switch devices 5a, 5b, 5c, 5d and the ground connection switch devices 6a, 6b by the microprocessor 4 will be described. , 1c, 1d will be described with reference to the timing chart shown in FIG.
The opening / closing control of the battery side switching devices 3a, 3b, 3c, 3d is executed by the output signal indicated by “HC” of the microprocessor 4, and the opening / closing control of the capacitor side switching devices 5a, 5b, 5c, 5d is performed by the microprocessor 4. The output signals indicated by “SC4”, “SC3”, “SC2” and “SC1” are respectively executed, and the open / close control of the ground connection switch devices 6a and 6b is output indicated by “GC2” and “GC1” of the microprocessor 4. Each is executed with a signal (see FIG. 1).
In the timing chart of FIG. 2, for each output signal of the microprocessor 4, each switch device is in a closed state (ON state) at “H level”, and each switch device is in an open state (OFF state) at “L level”. Furthermore, each timing in the control is shown with numbers “1” to “10” attached to the upper part.

Before the voltage detection sequence for the assembled battery 1 is started, all the switch devices are in an open state (off state).
When the voltage detection sequence is started, the microprocessor 4 first closes the battery side switch devices 3a, 3b, 3c, 3d at the timing of “1” in FIG. The respective capacitors 2a, 2b, 2c, and 2d are charged with the battery voltages of the unit cells 1a, 1b, 1c, and 1d.
After this charging is completed, the battery side switch devices 3a, 3b, 3c, 3d are switched to the open state (off state) at the timing “2”, and the capacitors 2a, 2b, 2c, 2d are switched to the single cells 1a, 1b, Separate from 1c and 1d.
Thereafter, control is performed so that the holding voltages of the charged capacitors 2a, 2b, 2c, and 2d are input to the input terminals 4a and 4b.

That is, first, the capacitor-side switch device 5d is closed (ON state) at the timing “2” by the output signal “SC1”.
As a result, the voltage of the capacitor 2d is input to the input terminal 4b indicated by "A / D1" of the microprocessor 4, and the microprocessor 4 is within the period between the timings of "2" and "3". The voltage between the ground and the input terminal 4b (that is, the voltage of the single cell 1d) is taken in as digital data.

Next, the ground connection switch device 6b is closed (ON state) at the timing of "3" by the output signal of "GC1".
Since the capacitor-side switch device 5d maintains the closed state (ON state), the low potential side of the capacitor 2c is connected to the ground, and the charge of the capacitor 2d is discharged.
Thereafter, the capacitor-side switch device 5c is closed (ON state) at the timing “4” by the output signal “SC2”.
As a result, the high potential side of the capacitor 2c is connected to the input terminal 4a indicated by “A / D2” of the microprocessor 4, and the microprocessor 4 is within the period between the timing “4” and the timing “5”. The voltage between the ground and the input terminal 4a (that is, the voltage of the single cell 1c) is taken in as digital data.

Next, according to the output signal “GC2”, the ground connection switch device 6a is closed (ON state) at the timing “5”, the low potential side of the capacitor 2b is connected to the ground, and the charge of the capacitor 2c is discharged. The
Thereafter, at the timing “6”, the ground connection switch device 6b is opened (OFF state) by the output signal “GC1” and the capacitor side switch device 5d is opened (OFF state) by the output signal “SC1”. After that, the capacitor-side switch device 5b is closed (ON state) by the output signal “SC3”.
As a result, the high potential side of the capacitor 2b is connected to the input terminal 4b indicated by “A / D1” of the microprocessor 4, and the microprocessor 4 is within the period between the timing “6” and the timing “7”. The voltage between the ground and the input terminal 4b (that is, the voltage of the unit cell 1b) is taken in as digital data.
At this time, since the capacitor-side switch device 5d and the ground connection switch device 6b are in the open state (off state), interference through these switch devices does not occur.

Next, according to the output signal “GC1”, the ground connection switch device 6b is closed (ON state) at the timing “7”, the low potential side of the capacitor 2a is connected to the ground, and the charge of the capacitor 2b is discharged. The
Thereafter, at timing “8”, the ground connection switch device 6a is opened (OFF state) by the output signal “GC2”, and the capacitor side switch device 5c is opened (OFF state) by the output signal “SC2”. After that, the capacitor-side switch device 5a is closed (ON state) by the output signal “SC4”.
As a result, the high potential side of the capacitor 2a is connected to the input terminal 4a indicated by “A / D2” of the microprocessor 4, and the microprocessor 4 is within the period between the timing “8” and the timing “9”. The voltage between the ground and the input terminal 4a (that is, the voltage of the unit cell 1a) is taken in as digital data.
At this time, since the capacitor side switch device 5c and the ground connection switch device 6a are in the open state (off state), interference through these switch devices does not occur.
After that, at the timing “9”, the ground connection switch device 6a is closed (ON state) by the output signal “GC2”, the capacitor 2a is discharged, and all the switch devices are opened at the timing “10”. As an (off state), the voltage detection sequence is terminated.

Summarizing the voltage detection sequence of the capacitors 2a, 2b, 2c, and 2d, the microprocessor 4 connects the low potential side of each of the capacitors 2a, 2b, 2c, and 2d to the ground and the high potential side as the input. Capacitor-side switch devices 5a, 5b, and 5c are sequentially repeated from the low potential side to the high potential side for the plurality of (four) capacitors 2a, 2b, 2c, and 2d. , 5d and the ground connection switch devices 6a, 6b are controlled to open and close.
By this open / close control, the holding voltages of the capacitors 2a, 2b, 2c, and 2d charged in the unit cells 1a, 1b, 1c, and 1d are input to the input terminals 4a and 4b.

[Another embodiment]
Hereinafter, other embodiments of the present invention will be listed.
(1) In the above embodiment, the case where analog switches are provided as the ground connection switch devices 6a and 6b arranged in the middle of the ground connection wiring GC is exemplified. , 6b, the parallel data output port provided in the microprocessor 4 can be used as the ground connection switch devices 6a, 6b because of the circuit arrangement in which one terminal is connected to the ground.
The parallel data output port for this purpose may be any output port that can create a high-impedance state such as a three-state output, open drain, or open collector.
FIG. 3 shows a circuit diagram when the ground connection switch devices 6a and 6b in the circuit of FIG. 1 are replaced with parallel data output ports.
The circuit diagram shown in FIG. 3 shows the case where a microprocessor 4 having a specification in which the parallel data output port and the input port of the A / D converter are shared by one terminal is used. When using, the wiring itself can be greatly simplified.
The control operation for voltage detection in the circuit of FIG. 3 is exactly the same as in the above embodiment.

(2) In the above embodiment, analog switches are exemplified as switch devices such as battery side switch devices 3a, 3b, 3c, and 3d, but various switch devices such as mechanical switches can be used.
(3) In the above embodiment, the case where the plurality of capacitors 2a, 2b, 2c, 2d are grouped into two groups is illustrated, but they may be grouped into three groups or more.

(4) In the above embodiment, the microprocessor 4 incorporating the A / D converter is used, and the function as the voltage detection element SD and the function as the switch control device CC are shared by the microprocessor 4. Although illustrated, it is good also as a structure provided with the A / D converter as the element SD for voltage detection separately from the microprocessor 4 which functions as switch control apparatus CC.
(5) In the above embodiment, the capacitors 2a, 2b, 2c, and 2d are controlled to be charged at the same timing. However, as long as the measurement error due to variations in detection time is within an allowable range. The capacitors 2a, 2b, 2c and 2d need not be charged at the same timing.

The circuit diagram concerning an embodiment of the invention Timing chart according to an embodiment of the present invention The circuit diagram concerning another embodiment of the present invention. Circuit diagram for explaining the prior art

Explanation of symbols

1 assembled battery 1a, 1b, 1c, 1d cell 2a, 2b, 2c, 2d capacitor 3a, 3b, 3c, 3d battery side switch device 4a, 4b input terminal 5a, 5b, 5c, 5d capacitor side switch device 6a, 6b Switch device for ground connection CC Switch control device GC Wiring for ground connection SC Wiring for voltage detection SD Voltage detection element

Claims (2)

A capacitor connected in parallel to each unit cell in an assembled battery in which a plurality of unit cells are connected in series;
A plurality of battery-side switch devices that are arranged in the middle of the wiring between the positive electrode side of each unit cell and each of the capacitors and turn on and off the wiring; and
Corresponding to each of the plurality of capacitors connected in series, energization of the wiring is arranged in the middle of the voltage detection wiring from the high potential side of each of the capacitors to the input terminal of the voltage detection element. A plurality of capacitor-side switch devices for turning on and off,
A plurality of ground connection switch devices arranged in the middle of the ground connection wiring for connecting the voltage detection wiring to the negative electrode side of the entire assembled battery, and turning on / off the wiring;
A switch control device for controlling opening and closing of the battery side switch device, the capacitor side switch device and the ground connection switch device;
The switch control device switches the battery-side switch device to an open state after charging the plurality of capacitors with the battery-side switch device in a closed state, and then supplies the holding voltage of each charged capacitor to the input terminal A voltage detection device for an assembled battery configured to control opening and closing of the capacitor side switch device and the ground connection switch device so as to input,
For a plurality of the capacitors grouped into a plurality of groups so that adjacent capacitors do not belong to the same group in the order of arrangement by potential,
In the voltage detection wiring, in the portion closer to the input terminal than the capacitor side switching device, wiring corresponding to the capacitors belonging to the same group is combined into one and connected to the same input terminal. ,
The ground connection wiring is connected to the input terminal side of the capacitor-side switching device in the voltage detection wiring for each group,
The switch control device performs an operation of connecting a low potential side of each of the capacitors to the negative electrode side of the entire assembled battery and connecting a high potential side to the input terminal from the low potential side to the high potential side. The assembled battery voltage detecting device is configured to open and close the capacitor-side switch device and the ground connection switch device so as to be sequentially repeated to the side.   The assembled battery voltage detection device according to claim 1, wherein the plurality of groups are divided into two groups: an odd-numbered group and an even-numbered group in the order of arrangement in terms of potential.

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