JP2006129577A - Cell balancer, its method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cell balancer, which can compensate the cell balance of a secondary cell for a mobile object with high accuracy, and its method and a program. <P>SOLUTION: This is a cell balancer which equalizes the residual capacity between the cells of a battery pack where a plurality of cells 10 are connected in series, being used for a battery pack for a power source of a mobile object. This is equipped with a constant current source 20, a voltage sensor 30 which detects the voltage value of each cell 10, and a voltage monitor 40 which acquires the voltage value of each cell 10 from the voltage sensor 30 during stoppage of the mobile object and localizes the charge target cell into which to replenish a current, based on these voltage values, and makes the charge target cell supplied with a current from the constant current source 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cell balance device, method, and program suitable for an assembled battery such as a secondary battery used as a driving power source for a moving body such as an HEV (Hybrid Electric Vehicle) or an electric forklift.

When a secondary battery is overcharged or overdischarged, life deterioration and safety problems occur. In an assembled battery system, even if the same power is charged / discharged due to variations in the remaining capacity of each battery, a battery that is overcharged / overdischarged appears. Such equalization of the remaining capacity is called “cell balance correction”).
As a cell balance correction method, it is conventionally known to correct the voltage balance of an assembled battery using a capacitor. For example, Japanese Patent Laying-Open No. 2003-189495 (Patent Document 1) discloses a charge / discharge control device using a capacitor.
According to this invention, a plurality of unit capacitors are connected in series as a cell to form a combined power supply, and an adjustment cell that can be charged / discharged with respect to each cell of the combined power supply, and the adjustment cell are individually connected to the combined power supply. Connecting means for connecting to each cell, and controlling the connecting means so that the adjustment cell is connected to each cell of the assembled power supply in order.
With this configuration, the voltage of each cell is equalized by charging / discharging between the adjustment cell and each cell, and overdischarge and overcharge due to variations in the remaining capacity of the cell are prevented.
JP 2003-189495 A

However, the conventional cell balance correction method as described above has a problem that it is difficult to apply to a high-power secondary battery used as a power source for driving a moving body for the following reasons.
First, when performing cell balance during charging / discharging in a high-power secondary battery, it is necessary to perform cell balance correction with a relatively large current. However, if the conventional cell balance device is applied as it is, the circuit scale is reduced. It gets bigger.
Secondly, a high-power secondary battery for a moving body is repeatedly charged (regenerated) / discharged (powering) with a large current in a short time. In such a high-power secondary battery, the cell voltage is not stable due to the internal resistance of the cell or the influence of a chemical reaction, so that an error occurs in the measured value of the cell voltage. For this reason, cell balance correction cannot be performed with high accuracy.

  The present invention has been made in view of such circumstances, and provides a cell balance apparatus, method, and program capable of performing cell balance correction of a secondary battery for a mobile body with high accuracy. Objective.

In order to solve the above problems, the present invention employs the following means.
The present invention is a cell balance device that is used in an assembled battery for a driving power source of a mobile body and equalizes the remaining capacity between the cells of the assembled battery configured by connecting a plurality of cells in series, A constant current source, a voltage sensor for detecting a voltage value of each cell, and a charge for acquiring a voltage value of each cell from the voltage sensor and supplementing a current based on the voltage value while the moving body is stopped A cell comprising cell specifying means for specifying a target cell, and control means for supplying a current from the constant current source to the charge target cell specified by the cell specifying means while the moving body is stopped Provide a balancing device.

According to the present invention, the cell specifying unit acquires the voltage value of each cell from the voltage sensor while the moving body is stopped. Here, since no current flows through the assembled battery while the moving body is stopped, it is possible to acquire an accurate cell voltage with few errors. In this way, the cell specifying means specifies the charging target cell to which the current is to be supplied by comparing the accurately measured cell voltage values with each other. One or two or more cells may be specified at this time. The control means supplies current from the constant current source to the charge target cell specified by the cell specifying means. As a result, the voltage of the cell supplied with the current increases, and as a result, the voltage value (remaining capacity) of the assembled battery can be equalized.
Examples of the cell include a secondary battery such as a lithium ion battery, a capacitor, and a double layer capacitor.

In the cell balance device described above, the cell specifying unit compares the voltage value of each cell acquired from the voltage sensor, and the voltage is the lowest among the cells whose voltage value is lower than the set value by a value higher than the highest voltage cell. It is preferable to specify a cell having a low value as a cell to be charged.
In this way, since the current is supplied from the cell having the lowest voltage value, the remaining capacity of the cell can be made uniform efficiently. It should be noted that charging is not performed when there is no cell having a voltage value lower than the maximum voltage cell by a predetermined value or more.

In the cell balance device described above, the constant current source is provided corresponding to each cell constituting the assembled battery, and the control unit activates the constant current source corresponding to the charging target cell. It is preferable to supply current from the constant current source to the charging target cell.
Thus, by providing a constant current source corresponding to each cell, it becomes possible to supply a current to the charging target cell quickly, so that the time required for equalization can be shortened.

In the cell balance apparatus described above, the assembled battery is divided into a plurality of modules each having a plurality of cells, and the constant current source, the cell specifying unit, and the control unit are provided for each module. The constant current source is connected to each of the cells via switching means, and the cell specifying means compares the voltage value of each cell constituting the module and outputs a voltage higher than the highest voltage cell. The cell having the lowest voltage value among the cells whose values are lower than the set value is specified as the charging target cell, and the control means is configured to specify the charging target cell specified by the cell specifying means while the moving body is stopped. It is preferable that current is supplied from the constant current source by operating the switching means that connects the constant current source to the constant current source.
As described above, since all the cells constituting the assembled battery are divided into a plurality of modules and uniformized for each module, the processing of the cell specifying means and the control means can be reduced. As a result, the remaining capacity can be equalized quickly.

In the cell balance apparatus described above, the cell specifying means provided corresponding to each module are connected to each other through an information transmission medium, and transmit and receive a voltage value of the cells to each other. The highest voltage value among all the cells constituting the battery is specified, a cell having a voltage value lower than the highest voltage value by a predetermined value or more is selected from its own module, and the lowest cell among the selected cells Is preferably specified as the charging target cell.
In this way, each cell specifying means can share the voltage values of all the cells constituting the assembled battery by mutually transmitting and receiving the voltage values of the cells that it owns. Even variations in remaining capacity can be eliminated. This makes it possible to equalize the remaining capacity of the cells as a whole assembled battery.

In the cell balance device described above, it is preferable that the constant current source is supplied with driving power from a battery or an assembled battery in the module.
Thus, by receiving the driving power of the constant current source from the battery or the assembled battery in the module, it is not necessary to provide an external power supply device, and it is possible to avoid an increase in the size of the device.

In the cell balance device described above, it is preferable that the constant current source is supplied with driving power from a predetermined external power supply device.
Thus, by receiving the driving power of the constant current source from the external power supply device, it becomes possible to equalize the remaining capacity of the cells without reducing the power of the assembled battery.

In the cell balance device described above, the current value of the constant current source is preferably variable.
In general, when charging is performed with a large current, the time required for equalization is shortened while the power loss is increased. Therefore, when charging ideally, it is preferable to perform charging with a current value as small as possible in consideration of the charging time.
According to the present invention, it is possible to set an appropriate current value by making the current value of the constant current source variable, so that it is possible to increase the efficiency of cell balance correction, that is, equalization of the remaining capacity. It becomes.

In the cell balance device described above, it is preferable that the control unit changes a current value supplied from the constant current source based on a state of the cell constituting the assembled battery and an estimated stop time.
Since the control means automatically sets the current value of the constant current source based on the state of the cell constituting the assembled battery and the estimated stop time, the current of the appropriate current value according to the state of the assembled battery is set. Thus, it is possible to equalize the remaining capacity between cells.
The cell state includes capacity degradation. This capacity deterioration can be estimated based on the voltage change of the cell.

In the cell balance device described above, the cell specifying unit acquires a voltage value of each cell from the voltage sensor after a lapse of a predetermined time from the stop of the moving body, and replenishes a current based on these voltage values. It is preferable to specify the cell.
Generally, the voltage of the cell is not stable immediately after the moving body is stopped due to the influence of internal contact resistance, chemical reaction, and the like. Therefore, by acquiring the voltage value of each cell from the voltage sensor after a lapse of a predetermined time from the stop of the moving body, it becomes possible to specify the charging target cell based on the accurate voltage value after the voltage is stabilized. Thereby, it is possible to improve the accuracy of equalizing the remaining capacity.

In the cell balance device described above, the cell specifying unit monitors the voltage of the cell or the battery pack after the moving body is stopped, and the time change rate of the cell voltage or the battery pack voltage is below a predetermined value. It is preferable that the voltage value of each cell is acquired from the voltage sensor at or after that time, and the charging target cell to be replenished with current is specified based on these voltage values.
As described above, by monitoring the time change rate of the cell voltage, it is possible to accurately grasp the timing at which the cell voltage is stabilized. As a result, it is possible to eliminate a reduction in equalization accuracy due to internal resistance, chemical reaction, or the like.

  The present invention comprises an assembled battery configured as a plurality of cells connected in series and used as a driving power source for a moving body, and a cell balance device for equalizing the remaining capacity between the cells of the assembled battery, The cell balance device acquires a voltage value of each cell from the voltage sensor while the moving body is stopped, a constant current source, a voltage sensor that detects a voltage value of each cell, and based on these voltage values A cell specifying means for specifying a charge target cell for replenishing current, and a control for supplying current from the constant current source to the charge target cell specified by the cell specifying means while the moving body is stopped And a power storage device comprising the means.

  The present invention is a cell balancing method for equalizing the remaining capacity between the cells of the assembled battery, which is used in an assembled battery for a driving power source of a mobile body, and a plurality of cells are connected in series, While the moving body is stopped, the voltage value of each cell is detected, and based on the detected voltage value of each cell, the charging target cell to be replenished with current is specified. A cell balance method for supplying a current from a constant current source to a charge target cell is provided.

  The present invention is used in an assembled battery for a driving power source of a mobile body, and executes a cell balancing process for equalizing the remaining capacity between the cells of the assembled battery configured by connecting a plurality of cells in series. A cell balance program for acquiring a voltage value of each cell detected by a voltage sensor while the moving body is stopped, and a current based on the acquired voltage value of the cell. A cell balance program comprising: a charge target cell specifying step for specifying a charge target cell to be replenished; and a control step for supplying a current from a constant current source to the charge target cell while the moving body is stopped. .

According to the cell balance device, method and program of the present invention, when the moving body stops, the constant current power source is activated to supply the current to the charging target cell, so that the measurement is caused by the internal resistance or chemical reaction of the cell. It becomes possible to eliminate the error. Thereby, cell balance correction can be realized with high accuracy.
In addition, since the cell balance correction is performed only while the vehicle is stopped, charging with a large current is not necessary, and an increase in size of the apparatus can be avoided.

  Hereinafter, an embodiment of a cell balance device of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a configuration diagram of a cell balance device according to a first embodiment of the present invention.
As shown in FIG. 1, the cell balance device according to the present embodiment includes a plurality of modules 11 in which a plurality of cells 10 are connected in series (here, as an example, the modules connected to the Kth and K + 1th are illustrated). The remaining capacity between the cells of the battery pack constituted by connecting the two in series is equalized. Here, examples of the cell 10 include a secondary battery such as a lithium ion battery, a capacitor, and a double layer capacitor.
The cell balance device of this embodiment includes a constant current source 20, a voltage sensor 30, and a voltage monitoring unit 40. One constant current source 20 and one voltage monitoring unit 40 are provided for each module 11. One voltage sensor 30 is provided corresponding to all the cells 10 constituting the assembled battery.

The constant current source 20 is connected to each cell 10 constituting the corresponding module 11 via the switching element 60. For example, as shown in FIG. 2 or FIG. 3, the constant current source 20 is configured by using an amplifier, a constant voltage element, a transistor, and the like, and supplies a current to a cell by controlling the current value to be constant. Note that the specific configuration example of the constant current source 20 is not limited to the above example, and can be appropriately designed by those skilled in the art according to the mounting. For example, in addition to the above example, a dedicated IC for battery charge control can be used.
The constant current source 20 is connected to the assembled battery via the insulation type DC / DC converter 50 shown in FIG. 1, and receives driving power from the assembled battery. Specifically, the voltage of the assembled battery is stepped down to a predetermined voltage by the insulated DC / DC converter 50 and supplied to the constant current source 20.

The voltage sensor 30 measures the voltage value of each cell 10 and outputs the voltage value to the voltage monitoring unit 40 provided corresponding to the module 11 to which the cell belongs.
The voltage monitoring unit 40 is composed of one or more logic circuits having a CPU and other voltage comparison circuits. The voltage monitoring unit 40 acquires the cell voltage value from the voltage sensor 30, compares the voltage value of the cell 10 constituting the module 11, and outputs an activation signal for activating the constant current source 20 according to a predetermined condition described later. In addition, a switching signal is output to the switching element.
Specifically, the voltage monitoring unit 40 compares the respective voltage values acquired from the voltage sensor 30 and selects a cell whose voltage value is lower than the set voltage by a value that is lower than the highest voltage cell. Activates (turns on) the switching element 60 provided between the function (cell identification means) that identifies the cell with the lowest voltage value as the cell to be charged and the charging target cell identified as the cell to be charged and the constant current source 20 ) To supply a current to the charging target cell from the constant current source 20 (control means).

Next, the operation of the cell balance device according to this embodiment will be described.
First, the assembled battery is mounted on a moving body such as an HEV (Hybrid Electric Vehicle) or an electric forklift, and is used as a driving power source for a traveling motor of the moving body. Then, the cell balance device according to the present embodiment is mounted on the moving body together with the assembled battery, and when the moving body stops, the assembled battery is replenished with current to a predetermined cell with a small remaining capacity. Is intended to equalize the remaining capacity of all cells.
In this embodiment, the remaining capacity is equalized for each module 11 constituting the assembled battery. Here, in an assembled battery in which a plurality of modules are connected in series, the module 11 connected in the (K + 1) th order will be described as an example, and the operation of the cell balance device will be described.
First, when the moving body is stopped, the cell voltage is measured by the voltage sensor 30 provided corresponding to each cell 10, and this voltage measurement value is provided corresponding to the module 11. Is input. Here, whether or not the moving body has stopped is determined based on, for example, whether or not the current flowing through the assembled battery has become zero, or the operation of an ignition key.

The voltage monitoring unit 40 compares the input voltage values of all the cells 10 belonging to the module 11 and selects a cell 10 having a voltage lower than a highest voltage cell by a predetermined value (for example, 25 mV) from among the cells. As a result, if there is one selected cell, this cell is specified as a charge target cell. Then, by turning on the switching element 60 corresponding to the charging target cell 10, the charging target cell and the constant current source 20 are connected, and then a start signal is output to the constant current source 20, whereby the constant current source 20 is output. The current source 20 is activated.
As a result, a current is supplied to the charging target cell from the constant current source 20, and the difference in remaining capacity (voltage difference) from other cells is gradually eliminated. The voltage monitoring unit 40 stops the current supply when the voltage difference between the voltage value of the charging target cell and the maximum voltage value becomes 15 mV or less.

On the other hand, when there are a plurality of cells 10 having a voltage of 25 mV (millivolt) or more lower than the highest voltage cell 10 in the module 11, the voltage monitoring unit 40 sequentially selects the cell 10 having the lowest voltage value in each module. And the constant current source 20 and the charging target cell are connected by turning on the switching element 60 corresponding to the charging target cell. Thereby, a current flows from the constant current source 20 to the charge / discharge cell, and the voltage value of the charge / discharge cell gradually increases. The voltage monitoring unit 40 stops the current supply to the cell when the voltage difference between the voltage value of the charging target cell and the maximum voltage value becomes 15 mV or less. Subsequently, at this time, the cell having the lowest voltage value is specified as the charging target cell, and the current supply from the constant current source 20 is started for this cell as described above.
The current supply from the constant current source is repeated until there is no cell having a voltage of 25 mV or more lower than that of the highest voltage cell in the module 11 or until the moving body starts running.

As described above, the cell balance device according to the present embodiment has the following effects.
First, based on the cell voltage detected while the moving body is stopped, the charging target cell that needs to be charged is identified and the remaining capacity of the cell is equalized. A voltage measurement error does not occur, and a highly accurate voltage value can be measured. Thereby, the remaining capacity of each cell can be equalized with high accuracy. Furthermore, since charging can be performed slowly over a relatively long time by performing charging while the moving body is stopped, charging can be performed with a charging current with a small current value. This makes it possible to avoid an increase in the size of the cell balance device.
Second, since the constant current source 20 is installed for each module, the number of constant current sources 20 can be reduced, and the manufacturing cost can be greatly reduced.

[Second Embodiment]
Next, a cell balance device according to a second embodiment of the present invention will be described.
In the cell balance device according to the first embodiment described above, each voltage monitoring unit 40 individually equalizes the remaining capacity of each cell constituting each module.
On the other hand, in the cell balance device according to the present embodiment, as shown in FIG. 4, the voltage monitoring units 40 provided in the respective modules 11 are respectively connected via the information transmission medium 70. .

Hereinafter, the operation of the cell balance device according to the present embodiment will be described.
First, when the voltage monitoring unit 40 provided corresponding to each module 11 acquires the voltage measurement value of each cell from the voltage sensor 30, the voltage monitoring unit 40 holds these voltage measurement values and also controls the other voltage monitoring units 40. These voltage measurement values are transmitted through the information transmission medium 70. Each voltage monitoring unit 40 executes transmission / reception of this information, whereby each voltage monitoring unit 40 acquires voltage measurement values of all cells constituting the assembled battery.
The voltage monitoring unit 40 extracts the maximum voltage value from the voltage measurement values of all the cells constituting the assembled battery. Subsequently, in the cell in the module 11 to which the self belongs, a cell having a voltage value lower than a predetermined value (for example, 25 mV) with respect to the maximum voltage value is selected, and the first cell described above is sequentially applied to the selected cell. Similarly to the cell balance device according to the embodiment, by supplying current from the constant current source 20, the remaining capacity of each cell is equalized.

  As described above, according to the cell balance device of the present embodiment, the cell having the highest voltage value is extracted from all the cells constituting the assembled battery, and charging should be performed based on the highest voltage value. Since the cells are selected and the selected cells are charged sequentially, it is possible to eliminate the variation in the remaining capacity between the modules 11. Thereby, equalization of the remaining capacity as the whole assembled battery can be realized.

[Third Embodiment]
Next, a cell balance device according to a third embodiment of the present invention will be described.
In the cell balance device according to this embodiment, the current value of the constant current source 20 is variable in the cell balance device according to the second embodiment shown in FIG.
Specifically, as shown in FIG. 5, a constant current setting device 80 that can manually change the current value of the constant current source 20 is added to the voltage monitoring unit 40. When the voltage monitoring unit 40 outputs an activation signal to the constant current source 20, the voltage monitoring unit 40 adds and outputs a current value command based on the current value set by the constant current setting unit 80. Accordingly, the constant current source 20 that has received the activation signal supplies a current having a current value based on the current value command to the charging target cell.
As described above, according to the cell balance device according to the present embodiment, the current value of the constant current source 20 is made variable so that the cell can be supplied with an appropriate current value according to variations in the remaining capacity of the cell. Therefore, it is possible to increase the efficiency of equalization.

As described above, in addition to the method of manually setting the current value, for example, a constant current setting function for outputting an appropriate current value command is added to the voltage monitoring unit 40, thereby automatically The current value may be set.
In this case, the voltage monitoring unit 40 sets the current value of the constant current 20 according to the state of the cell and the estimated stop time. For example, the current value is set to be smaller as the estimated stop time is longer, and the current value is set to be larger as the variation of the cell state, for example, the remaining capacity is larger.
Since it is preferable to set the charging current as small as possible, the voltage monitoring unit 40 sets the current value of the constant current source 20 to the minimum current value at which the equalization of the remaining capacity can be completed during the estimated stop time.

The estimated stop time can be estimated based on, for example, the traveling state so far. Specifically, it is possible to hold the stop time of the vehicle every time and adopt the average stop time so far as the estimated stop time.
Here, the “vehicle stop time” is a period during which the vehicle is stopped due to a signal waiting or the like, that is, when the stop time is relatively short, and after the vehicle is parked until the next vehicle is run. It is roughly divided into a period, that is, a case where the stop time is relatively long.
This can be distinguished, for example, between when the ignition key is on and when it is off. Therefore, it is preferable to provide two modes for the case where the ignition key is turned on and the case where the ignition key is turned off, and to divide the estimated stop time to be adopted according to the on / off state of the ignition key. As a result, it is possible to avoid setting an inappropriate current value by adopting a long estimated time in spite of the stop due to signal waiting.

As described above, the voltage monitoring unit 40 automatically sets the current value of the constant current source 20 based on the state of the cells constituting the assembled battery (for example, the deterioration state) and the estimated stop time. Accordingly, it is possible to equalize the remaining capacity between the cells with a current having an appropriate current value according to the state of the assembled battery.
Further, according to this method, the current value can be changed following the traveling state of the moving body, so that charging can be realized at an appropriate current value.

[Fourth Embodiment]
Next, a cell balance device according to a fourth embodiment will be described.
As shown in FIG. 6, in the cell balance device according to the present embodiment, the voltage monitoring unit 40 further includes a timer 90 in the cell balance device according to the second embodiment described above. The voltage monitoring unit 40 starts the timer 90 when the moving body stops, acquires each voltage value from the voltage sensor 30 after a predetermined time elapses, and compares these acquired voltage values. Then, the charging target cell is specified. A current is supplied from the constant current source 20 to the charging target cell.

As a cell constituting the assembled battery, a lithium ion battery that charges and discharges electric power by using a chemical reaction is generally employed. In such a cell, even after the current stops flowing, the inter-cell voltage changes due to the influence of a chemical reaction inside the cell. That is, it takes time for the cell voltage to settle to a constant value after the current stops flowing.
In the cell balance device according to the present embodiment, the cell voltage is not acquired immediately after the moving body stops, but the cell voltage is acquired from the voltage sensor after a predetermined time has elapsed since the moving body stopped, and this acquisition is performed. A charging target cell to be charged is specified based on the cell voltage. And charging from a constant current source is performed with respect to the specified charging / discharging object cell.
Thus, since the charge target cell is specified based on the cell voltage after the cell state is stabilized, the measurement error due to the influence of the chemical reaction can be eliminated. As a result, the remaining capacity (cell voltage) can be accurately detected, so that the equalization of the remaining capacity of the cells can be realized with high accuracy.

In addition to the method using the timer 90 described above, for example, when the voltage change rate of each cell becomes a predetermined value or less, the cell to be charged may be specified based on the voltage value at that time. . Specifically, the voltage monitoring unit 40 calculates the voltage change rate of each cell based on the voltage value of each cell acquired from each voltage sensor 30, and the voltage change rate of all the cells becomes a predetermined value or less. In this case, it is determined that the state of the cell is stable, and the charging target cell is specified based on the voltage value at this time.
Thus, by monitoring the voltage change rate, it becomes possible to grasp the state of the cell more accurately. As a result, measurement errors such as cell voltage due to chemical reaction can be further reduced, and equalization of the remaining capacity of the cell can be realized with higher accuracy.
Instead of the voltage change rate of each cell, the voltage change rate of the assembled battery and the voltage change rate of each module may be used.

As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.
First, a predetermined number of voltage monitoring units 40 are provided as appropriate according to the mounting. Specifically, the voltage monitoring unit 40 is provided corresponding to each module, or the voltage monitoring unit 40 is configured to monitor and control the voltages of all modules in a concentrated manner. It is conceivable to provide one for the device, that is, one for the assembled battery.
Second, the constant current source 20 may be provided corresponding to each cell, as shown in FIG. That is, one constant current source 20 may be provided for one cell 10. According to such a configuration, since the switching element 60 is not necessary, it is possible to eliminate a time loss due to switching of the switching element. Thereby, uniformization can be performed quickly.

  Third, the constant current source 20 may receive power from, for example, a battery in a module or a predetermined external power supply, in addition to receiving driving power from the assembled battery. Thus, by receiving the supply of the driving power of the constant current source from the external power supply device, it becomes possible to equalize the remaining capacity of the cells without reducing the power of the assembled battery. The external power supply device may be built in the cell balance device or provided outside.

Fourth, the voltage monitoring unit 40 includes, for example, a CPU (Central Processing Unit), ROM (Read
It may be configured by only memory (RAM), random access memory (RAM), or the like. In this case, a series of processes for realizing the various functions as described above by the voltage monitoring unit 40 is recorded in a ROM or the like in the form of a program, and the CPU reads the program into the RAM or the like to read information. By executing the processing / calculation processing, various functions described later are realized.
Fifth, instead of the insulated DC / DC converter 50, an AC / DC converter may be used. Further, a transformer may be used instead of the AC / DC converter.

It is a lineblock diagram of the cell balance device concerning a 1st embodiment of the present invention. It is a figure which shows one structural example of the constant current source shown in FIG. It is a figure which shows one structural example of the constant current source shown in FIG. It is a block diagram of the cell balance apparatus which concerns on the 2nd Embodiment of this invention. It is a block diagram of the cell balance apparatus which concerns on the 3rd Embodiment of this invention. It is a block diagram of the cell balance apparatus which concerns on the 4th Embodiment of this invention. It is a figure which shows the modification of the cell balance apparatus which concerns on one Embodiment of this invention.

Explanation of symbols

10 cell 11 module 20 constant current source 30 voltage sensor 40 voltage monitoring unit 60 switching element 70 information transmission medium 80 constant current setter 90 timer

Claims (15)

A cell balance device for equalizing a remaining capacity between the cells of the assembled battery, which is used in an assembled battery for a driving power source of a moving body, and a plurality of cells are connected in series,
A constant current source;
A voltage sensor for detecting the voltage value of each cell;
While the moving body is stopped, a cell specifying means for acquiring a voltage value of each cell from the voltage sensor and specifying a charging target cell for replenishing current based on the voltage value;
A control means for supplying a current from the constant current source to the charging target cell specified by the cell specifying means while the moving body is stopped.   The cell specifying means compares the voltage value of each cell acquired from the voltage sensor, and selects the cell with the lowest voltage value among the cells whose voltage value is lower than the maximum voltage cell by the set value. The cell balance device according to claim 1 specified as follows. The constant current source is provided corresponding to each cell constituting the assembled battery,
3. The cell balance device according to claim 1, wherein the control unit causes a current to be supplied from the constant current source to the charging target cell by activating the constant current source corresponding to the charging target cell. The assembled battery is divided into a plurality of modules having a plurality of cells,
For each module, the constant current source, the cell specifying unit, and the control unit are provided,
The constant current source is connected to each of the cells via switching means;
The cell identification means compares the voltage value of each cell constituting the module, and among the cells whose voltage value is lower than a set value by a value higher than the highest voltage cell, the cell having the lowest voltage value is set as the charging target cell. Identify,
The control unit activates the switching unit that connects the charging target cell specified by the cell specifying unit and the constant current source while the moving body is stopped, thereby supplying current from the constant current source. The cell balance device according to claim 1 to be supplied.   The cell specifying means provided corresponding to each module transmits and receives the voltage value of each cell, specifies the highest voltage value among all the cells constituting the assembled battery, and the highest voltage value The cell balance device according to claim 4, wherein a cell having a voltage value lower than a predetermined value is selected from its own module, and the lowest cell among the selected cells is specified as a charge target cell.   The cell constant device according to any one of claims 1 to 5, wherein the constant current source is supplied with driving power from a battery in the module.   The cell balance device according to any one of claims 1 to 5, wherein the constant current source is supplied with driving power from the assembled battery.   The cell balance device according to any one of claims 1 to 5, wherein the constant current source is supplied with driving power from a predetermined external power supply device.   The cell balance device according to any one of claims 1 to 8, wherein a current value of the constant current source is variable.   The said control means changes the electric current value supplied from the said constant current source based on the state and estimated stop time of the said cell which comprises the said assembled battery, The statement in any one of Claims 1-9 Cell balance device.   The cell specifying unit acquires a voltage value of each cell from the voltage sensor after a predetermined time has elapsed from the stop of the moving body, and specifies a charge target cell to be replenished with current based on these voltage values. The cell balance device according to claim 10.   The cell specifying means monitors the voltage of the cell or the battery pack after the mobile unit is stopped, and when the time change rate of the cell voltage or the battery pack voltage becomes a predetermined value or less, or after The cell balance device according to any one of claims 1 to 10, wherein a voltage value of each cell is acquired from a voltage sensor, and a charge target cell to be supplemented with current is specified based on the voltage value. A battery pack comprising a plurality of cells connected in series and used as a driving power source for a moving body, and a cell balance device for equalizing the remaining capacity between the cells of the battery pack,
The cell balance device includes:
A constant current source;
A voltage sensor for detecting the voltage value of each cell;
While the moving body is stopped, a cell specifying means for acquiring a voltage value of each cell from the voltage sensor and specifying a charging target cell for replenishing current based on the voltage value;
A power storage device comprising: control means for supplying current from the constant current source to the charging target cell specified by the cell specifying means while the moving body is stopped. A cell balance method for equalizing a remaining capacity between the cells of the assembled battery, which is used in an assembled battery for a driving power source of a moving body, and a plurality of cells are connected in series,
While the moving body is stopped, the voltage value of each cell is detected,
Based on the detected voltage value of each cell, identify the charging target cell to replenish the current,
A cell balance method in which a current is supplied from a constant current source to the specified charging target cell while the moving body is stopped. A cell that is used in an assembled battery for a driving power source of a moving body and causes a computer to execute a cell balance process for equalizing the remaining capacity between the cells of the assembled battery configured by connecting a plurality of cells in series A balance program,
A data acquisition step of acquiring a voltage value of each cell detected by a voltage sensor while the moving body is stopped;
Based on the acquired voltage value of the cell, a charging target cell specifying step for specifying a charging target cell for replenishing current;
A cell balance program comprising: a control step of supplying a current from a constant current source to a charge target cell while the moving body is stopped.

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