JP2013247690A - Voltage equalization device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a voltage equalization device in which the balance time of a balance circuit using an active system is shortened.SOLUTION: The voltage equalization device comprises: first active system balance circuits 404-406 for equalizing the voltage of a plurality of battery cells forming battery blocks 401-403; and a second active system balance circuit 407 for equalizing all battery cells forming a battery pack. When equalizing all battery cells forming a battery pack, the voltage equalization device performs balance operation of the first balance circuits 404-406 and the second balance circuit 407 simultaneously.

Description

  The present invention relates to a voltage equalizing device that equalizes the voltages of battery cells constituting an assembled battery, and more particularly to an active voltage equalizing device.

In order to obtain a high voltage, a hybrid vehicle, an electric vehicle, and the like are equipped with a battery pack in which a plurality of battery cells such as lithium ion batteries are connected in series.
When the voltage of the battery cells forming such an assembled battery varies, the deterioration of the battery cells may progress at an accelerated rate, or the amount of available energy may decrease. Therefore, it is desirable that the voltages of the battery cells forming the assembled battery are equalized. However, since the capacity, internal resistance, self-discharge rate, and the like are not uniform for each battery cell, the voltage of the battery cells forming the assembled battery may vary. Therefore, the voltage equalization control device having a balance circuit for equalizing the voltage of the battery cells forming the assembled battery is conventionally used to equalize the voltage of the battery cells forming the assembled battery (hereinafter referred to as voltage equalization). Is proposed).

  The cell equalization circuit of Patent Document 1 operates the discharge circuit based on the magnitude relationship between the voltages of the plurality of battery cells in the block. Thereby, the voltages of the plurality of battery cells in the block are equalized. On the other hand, a high voltage block is extracted by the voltage detection circuit. And the adjustment apparatus of the assembled battery which can accelerate | stimulate the discharge of a block with a high voltage by turning on the hardware which uses a block with a high voltage as a power supply is proposed.

  The voltage equalization apparatus of Patent Document 2 divides batteries connected in series into modules of a certain size, performs charge equalization in the module and charge equalization between modules at the same time, improves charge equalization performance, It has been proposed to reduce the size.

  In the voltage equalization circuit of Patent Document 3, adjacent battery blocks share two adjacent cells. Thus, it has been proposed that the voltage equalization of assembled batteries having various total cell numbers can be achieved by the high-speed and easy-to-use 4-cell equalization IC.

The secondary battery pack of Patent Document 4 performs voltage balance adjustment for each unit block or composite block during charging, and performs voltage balance adjustment between the secondary batteries in the unit block after stopping charging due to full charge. Thus, it has been proposed to obtain voltage balance in unit blocks or composite block units, voltage balance in secondary battery units, and voltage balance in the entire secondary battery block.
In the battery system in which a plurality of module batteries including a plurality of cell batteries each of which is connected in series in Patent Document 5 is connected, each of the plurality of module batteries has an inter-cell balance circuit that equalizes energy between the cell batteries. And an inter-module balance circuit for equalizing energy between the module batteries. Thereby, as a battery system, it has been proposed to shorten the discharge time for balancing energy.

  The power supply device of Patent Document 6 includes a plurality of power supply blocks having an equalization circuit that eliminates an unbalance of each battery of the series battery group, and the battery unbalance of each power supply block is eliminated by the equalization circuit. The power supply device further includes a block discharge circuit connected in parallel with the series battery group of each power supply block, and a block control circuit for controlling the block discharge circuit. A block control circuit equalizes the voltage of a series battery group by discharging a series battery group with the block discharge circuit connected to the series battery group with a high voltage. It has been proposed to eliminate the unbalance of all the batteries by forming the power supply device in this way.

  The charge control device of Patent Document 7 detects a minimum cell voltage from a plurality of cell batteries, a voltage difference from the minimum cell voltage is equal to or greater than a predetermined reference voltage difference Vth, and the cell voltage is a predetermined voltage. The bypass operation is performed on the cell battery having the bypass operation start voltage Vref or higher. Further, when the voltage difference between the cell voltage and the minimum cell voltage becomes equal to or less than the reference voltage difference Vth after the bypass operation is started, the bypass operation for the cell battery is stopped. Accordingly, it has been proposed to reduce the power loss associated with the bypass operation.

  As described above, in Patent Documents 1 to 7, the voltage of all the battery cells is equalized by equalizing the voltages of the battery cells forming the battery block and equalizing the voltages of the battery blocks forming the assembled battery. Are equalized.

JP 2009-278709 A JP 2010-529817 A JP-A-2005-312161 JP 2009-050085 A JP 2010-029050 A JP 2007-300701 A JP 2011-078276 A

  An object of the present invention is to shorten the balance time of a balance circuit using an active method.

  In order to solve the above-described problems and achieve the object, a set of b battery blocks in which a number of battery cells (a is a natural number of 2 or more) connected in series is connected in series (b is a natural number of 2 or more). A battery, an nth (n is a natural number from 1 to a-1) battery cell and an (n + 1) th battery cell of each of the battery blocks, a 2n-1 switch element and a 2n switch element connected in series Are connected in parallel, and the nth coil is connected between the nth battery cell and the (n + 1) th battery cell, and between the 2n-1 switch element and the 2nth switch element, a-1 first balance circuits, an m-th battery block (m is a natural number from 1 to b-1) and an m + 1-th battery block of the assembled battery, and a second m-1th battery block connected in series. The switch element and the 2m-th switch element are connected in parallel, and the m-th battery block is connected. B-1 second balance circuits in which the mth coil is connected between the first and m + 1th battery blocks and between the 2m-1st switch element and the 2mth switch element, A first switching control unit configured to switch the switch elements of the first balance circuit so that voltages of adjacent battery cells of the a battery cells forming the battery block are equalized; And a second switching control section that switches the switch elements of the second balance circuit so that the voltages of the adjacent battery blocks are equalized.

  According to the present invention, the balance time of the balance circuit using the active method can be shortened.

It is a block diagram which shows a voltage equalization apparatus. It is explanatory drawing which shows the memory content of a regulation value table. It is explanatory drawing which shows the change of the voltage of the battery cell at the time of operation | movement of a balance circuit. It is a block diagram which shows one Example of the voltage equalization apparatus which concerns on embodiment. It is an activity diagram which shows the voltage equalization processing procedure which concerns on embodiment. It is a flowchart which shows the voltage equalization process sequence of the battery cell which concerns on embodiment. It is a flowchart which shows the voltage equalization process sequence of the battery block which concerns on embodiment. It is a flowchart which shows the voltage equalization determination process which concerns on embodiment. It is explanatory drawing which shows the change of the voltage of the battery cell at the time of the voltage equalization process which concerns on embodiment.

Hereinafter, embodiments of a voltage equalizing apparatus according to the present invention will be described in detail with reference to the drawings.
(Embodiment)
First, features of the voltage equalizing apparatus according to the embodiment will be described.

  In an active balance circuit, the voltages of a plurality of battery cells forming an assembled battery are equalized by exchanging charges between adjacent battery cells. Therefore, when exchanging electric charges (energy) between distant battery cells, the electric charges must be transferred through several circuits. In this way, in the active balance circuit as described above, when charges are exchanged between distant battery cells, the charge is moved through a number of circuits. There is a problem that the movement efficiency decreases.

  Therefore, the voltage equalization apparatus according to the embodiment includes an active first balance circuit that equalizes voltages of a plurality of battery cells that form each battery block, and voltages of a plurality of battery blocks that form an assembled battery. And an active second balance circuit for equalizing the current. And when equalizing the voltage of all the battery cells which form an assembled battery, a voltage equalization apparatus operates a 1st balance circuit and a 2nd balance circuit simultaneously.

As a result, the voltage equalization apparatus according to the embodiment allows the number of circuits through which the charge passes by moving the charge through the second balance circuit even when the charge is exchanged between the separated battery cells. Can be reduced. Therefore, the voltage equalization apparatus according to the embodiment can shorten the balance time, which is the time until the voltages of the plurality of battery cells are equalized, and can improve the energy efficiency of the voltage equalization control.
<Circuit configuration of balance circuit>
First, the circuit configuration of an active balance circuit will be described.

FIG. 1 is a configuration diagram illustrating a voltage equalizing apparatus. The circuit configuration of FIG. 1 shows the minimum unit of an active balance circuit.
The voltage equalization apparatus 100 includes battery cells 101 and 102, switch elements 103 and 104, a coil 105, voltage measurement units 106 and 107, a main control unit 108, and a storage unit 111, and is an active type. A balance circuit is formed. Further, the main control unit 108 includes a variation determination unit 109 and a switching control unit 110. The switch elements 103 and 104 and the coil 105 are collectively referred to as a balance circuit 112.

The battery cells 101 and 102 are secondary batteries, such as a lithium ion secondary battery and a nickel hydride secondary battery, for example. The battery cells 101 and 102 are connected in series.
The switch elements 103 and 104 are, for example, semiconductor switches such as field effect transistors or electromagnetic relays. The switch elements 103 and 104 are connected in series and connected in parallel with the battery cells 101 and 102.

  The coil 105 is configured by, for example, winding an electric wire such as a copper wire. The coil 105 is connected between the battery cell 101 and the battery cell 102 and between the switch element 103 and the switch element 104.

  The voltage measuring units 106 and 107 are, for example, voltmeters. The voltage measuring units 106 and 107 are connected in parallel to the battery cells 101 and 102, respectively, and measure the voltage of the battery cells 101 and 102. In addition, the voltage measuring units 106 and 107 transmit the measured voltage values (hereinafter referred to as measured values) to the variation determining unit 109 and the switching control unit 110.

  The main control unit 108 is a computer in which a memory is mounted as a work space such as an ECU (Electronic Control Unit), for example, and controls the operation of each component of the voltage equalizing apparatus 100. Then, the computer is caused to function as the variation determination unit 109 and the switching control unit 110. In the main control unit 108, the variation determination unit 109 and the switching control unit 110 may be realized by circuits having respective functions.

The variation determination unit 109 is realized as a partial function of the main control unit 108. Then, the voltages measured by the voltage measuring units 106 and 107 are acquired, the voltage difference between the battery cells 101 and 102 is calculated by the following formula (1), and the voltage of the battery cells 101 and 102 is calculated by the following formula (2). It is determined whether or not the difference is within a specified value.
Voltage of battery cell 101−voltage of battery cell 102 = voltage difference (1)
Voltage difference ≤ specified value (2)
And the variation determination part 109 determines with the voltage of the battery cells 101 and 102 having varied, when the voltage difference of the battery cells 101 and 102 is larger than a regulation value. Then, the variation determination unit 109 outputs a signal (hereinafter referred to as a variation signal) indicating that the voltage difference between the battery cells 101 and 102 is larger than a specified value to the switching control unit 110. The variation signal may include the voltage values of the battery cells 101 and 102, respectively. Note that when the variation determination unit 109 is realized by a circuit, for example, a comparator may be used.

  The switching control unit 110 is realized as a partial function of the main control unit 108. When the variation signal is input from the variation determination unit 109, the switching control unit 110 acquires a measurement value from the voltage measurement units 106 and 107. Further, the switching control unit 110 refers to the acquired measurement value and compares the voltage of the battery cell 101 with the voltage of the battery cell 102. For example, when the switching control unit 110 determines that the voltage of the battery cell 101 is larger than the voltage of the battery cell 102, the switching control unit 110 outputs a first pulse signal to the switch element 103. The switching control unit 110 outputs the second pulse signal to the switch element 104 after the rising time of the first pulse signal. Then, the switch element 103 is turned on when the first pulse signal is at a high level, and is turned off when the first pulse signal is at a low level. The switch element 104 is turned on when the second pulse signal is at a high level, and is turned off when the second pulse signal is at a low level. Thereby, the switching control part 110 switches the switch elements 103 and 104 alternately. In the case where the switching control unit 110 is realized by a circuit, for example, a comparator and an oscillator may be used.

The storage unit 111 is, for example, a memory such as a ROM (Read Only Memory) and a RAM (Random Access Memory), or an HD (Hard Disk). And the memory | storage part 111 has memorize | stored the regulation value which is a threshold value of the voltage difference of the battery cells 101 and 102 at least. This specified value is read by the variation determination unit 109 when the variation determination unit 109 determines the voltage variation of the battery cells 101 and 102.
<Default value>
The specified value specifies the voltage difference between the battery cells that are subject to voltage equalization, and the voltage of the battery cell varies when the voltage difference becomes larger than the voltage value set in the specified value. Judge that it is. Hereinafter, setting of a prescribed value of the voltage difference and other setting values handled in the voltage equalization control will be described.

FIG. 2 is an explanatory diagram showing the stored contents of the specified value table.
The specified value table 201 only needs to store at least the specified value. However, in the specified value table 201 of FIG. 2, OCV (Open circuit voltage) that is the open voltage of the battery cell, and the remaining battery level are described in order to explain the specified value and other set values handled in the voltage equalization control An example is shown in which the SOC (State of Charge) indicating the ratio and the operation start voltage are stored. In addition, OCV and SOC differ for every kind of battery cell, and are values acquired by experiment. The specified value and the operation start voltage are values arbitrarily set by the user.

  The OCV and SOC values stored in the specified value table 201 indicate the characteristics of the battery cells used for the battery cells 101 and 102 as an example. Based on this characteristic, the user arbitrarily sets a specified value. In the specified value table 201, 100 [mV] is set as the specified value. The specified value varies depending on the characteristics of the battery cell to be used and the accuracy required for voltage equalization of the battery cell, but is set to several tens to several hundred mV, for example.

  Note that the OCV-SOC graph 202 in FIG. 2 shows the relationship with the OCV-SOC in the specified value table 201. Referring to the OCV-SOC graph 202, when the OCV is less than 3.5 [V], the amount of change in the SOC with respect to the change in the OCV is smaller than when the OCV is 3.5 [V] or more. Another specified value may be set. Alternatively, as shown in the specified value table 201, an operation start voltage for determining whether or not to perform a balance operation of moving charges by switching the balance circuit 112 is determined, and the OCV is 3.5 [ The battery cells less than V] may not be balanced. That is, with respect to battery cells whose voltage is equal to or lower than the operation start voltage, even if a variation in the battery cell voltage is confirmed by the variation determination unit 109, the balance operation is not performed and charges are not exchanged with other battery cells. And

Further, in consideration of overdischarge or overcharge of the battery cell, an operation start voltage for performing the balance operation of the battery cell and an operation end voltage for ending the balance operation may be determined. When the voltage of the battery cell is lower than the operation start voltage and higher than the operation end voltage, the corresponding battery cell is not balanced.
<Balance operation>
Here, with reference to FIG. 3, the balance operation | movement in the voltage equalization control of a voltage equalization apparatus is demonstrated in detail. In the following description, it is assumed that the voltage of the battery cell 101 is higher than the voltage of the battery cell 102. Note that the balance operation refers to an operation of switching the switch element to move charges between adjacent battery cells in the voltage equalization control of the battery cells. Further, it is assumed that the voltage values of the battery cells 101 and 102 are included in the variation signal. And when the operation start voltage is set, the voltage of the battery cells 101 and 102 shall be more than an operation start voltage.

FIG. 3 is an explanatory diagram showing changes in the voltage of the battery cell during the operation of the balance circuit.
In the balance operation graph 300 of FIG. 3, the horizontal axis is time [ms], and the vertical axis is voltage [V]. The balance operation graph 300 shows the relationship between the voltage change of the battery cells 101 and 102 during the balance operation, the first pulse signal, and the second pulse signal.

  First, the voltage equalization apparatus 100 determines whether or not the voltage difference between the battery cells 101 and 102 is greater than a specified value by the variation determination unit 109. When it is determined that the voltage difference between the battery cells 101 and 102 is greater than the specified value, a variation signal is input from the variation determination unit 109 to the switching control unit 110. Then, the switching control unit 110 acquires the voltage values of the battery cells 101 and 102 included in the variation signal, and determines that the voltage of the battery cell 101 is higher than the voltage of the battery cell 102.

  The switching control unit 110 outputs the first pulse signal to the switch element 103. Then, the switching control unit 110 outputs the second pulse signal to the switch element 104 when the on / off operation of the switch element 103 by the first pulse signal ends. Note that the rising times t [s] of the first pulse signal and the second pulse signal are set so that the charge can be transferred from the battery cell 101 to the battery cell 102 with the maximum efficiency.

  Then, when the control interval T [s] elapses, the switching control unit 110 outputs the first pulse signal to the switch element 103 again. Further, the switching control unit 110 outputs the second pulse signal to the switch element 104 when the on / off operation of the switch element 103 by the first pulse signal is completed.

By repeating the above operation, the switch elements 103 and 104 are switched, and the charge is transferred from the battery cell 101 to the battery cell 102.
Then, the switching control unit 110 repeats switching of the switch elements 103 and 104 until the voltage difference between the battery cells 101 and 102 becomes equal to or less than a specified value stored in the specified value table 201. Specifically, the switching control unit 110 reads a specified value from the specified value table 201 when starting switching of the switch elements 103 and 104. Moreover, the switching control part 110 acquires a measured value from the voltage measurement parts 106 and 107, and monitors the voltage of the battery cells 101 and 102 during balance operation. Then, the switching control unit 110 determines whether or not the voltage difference between the battery cells 101 and 102 is within a specified value. When the voltage difference between the battery cells 101 and 102 is less than the specified value, the switching elements 103 and 104 are determined. The switching operation is stopped and the balance operation is terminated. As described above, the voltages of the battery cells 101 and 102 are equalized as shown in the balance operation graph 300 of FIG. It should be noted that the specified value used for the end of switching of the switch elements 103 and 104 and the specified value used for the start of switching of the switch elements 103 and 104 may be set separately. For example, in balance operation, power is consumed based on efficiency. Therefore, the specified value used for switching start determination is set to be large so as not to perform balance operation as much as possible. In addition, by setting the specified value used in the switching end determination smaller than the specified value used in the switching start determination, the battery cell voltage difference is made smaller than the specified value used in the switching start determination. Increase the interval until the balance operation starts.
<Configuration of voltage equalization device>
A configuration of the voltage equalizing apparatus according to the embodiment will be described.

  FIG. 4 is a configuration diagram illustrating an example of the voltage equalization apparatus according to the embodiment. In the following description, the same components as those of the voltage equalizing apparatus having the minimum unit active type balance circuit 112 shown in FIG.

  The voltage equalization apparatus 400 according to the embodiment includes battery blocks 401 to 403, first balance circuits 404 to 406, a second balance circuit 407, a main control unit 408, and a storage unit 111. The main control unit 408 includes a first variation determination unit 409, a first switching control unit 410, a block voltage calculation unit 411, a second variation determination unit 412, and a second switching control unit 413. Have

  The battery blocks 401 to 403 have a configuration in which four battery cells are connected in series, and each is connected to a separate first balance circuit. And the battery blocks 401-403 are mutually connected in series and comprise the assembled battery. The battery cells included in the battery blocks 401 to 403 are connected to voltage measuring units (not shown) for measuring voltages. Each voltage measurement unit outputs a measured value of the voltage of the battery cell to which each voltage measurement unit is connected to the first variation determination unit 109 and the first switching control unit 110. In FIG. 4, three battery blocks are connected in series to form an assembled battery, but this is an example, and the number of battery blocks is not particularly limited as long as it is two or more. Further, in FIG. 4, four battery cells are connected in series to form a battery block, but this is an example, and the number of battery cells is not particularly limited as long as it is two or more. The configuration of the voltage measurement unit of the voltage equalization apparatus 400 is the same as that of the voltage measurement units 106 and 107 of the voltage equalization apparatus 100 described with reference to FIG. In the following description, for the sake of simplicity of explanation, the case where the number of battery blocks forming the assembled battery is three and the number of battery cells constituting each battery block is four will be described as an example.

  The first balance circuit 404 has a configuration in which the balance circuits 112 described in FIG. 1 are connected to each other so that charges can be transferred between adjacent battery cells included in the battery block 401. Specifically, if the battery cells included in the battery block 401 are arranged in the order of the battery cell a to the battery cell d, the battery cell a, b, the battery cell b, c, and the battery cell c, d A first balance circuit is formed by connecting the balance circuit 112 between them. The configurations of the first balance circuit 405 and the first balance circuit 406 are the same as the configuration of the first balance circuit 404. Note that the first balance circuits 404 to 406 in FIG. 4 do not include the battery blocks 401 to 403.

  The second balance circuit 407 has a configuration in which the balance circuits 112 described in FIG. 1 are connected to each other so that charges can be transferred between adjacent battery blocks 401 to 403 included in the assembled battery. Specifically, the second balance circuit 407 is formed by connecting the balance circuit 112 between the battery blocks 401 and 402 and the battery blocks 402 and 403, respectively.

  The main control unit 408 is a computer in which a memory is mounted as a work space such as an ECU (Electronic Control Unit), for example, and controls the operation of each component of the voltage equalizing apparatus 400. Then, the computer is caused to function as the first variation determination unit 409, the first switching control unit 410, the block voltage calculation unit 411, the second variation determination unit 412, and the second switching control unit 413. In the main control unit 108, the first variation determination unit 409, the first switching control unit 410, the block voltage calculation unit 411, the second variation determination unit 412, and the second switching control unit 413 May be realized by circuits having respective functions.

The first variation determination unit 409 is realized as a partial function of the main control unit 408. And the voltage which the voltage measurement part connected to the battery block 401 each acquired is acquired, The minimum voltage (henceforth a minimum cell voltage) in the acquired voltage of four battery cells, and the maximum voltage (henceforth). Hereinafter, the maximum cell voltage) is extracted. Then, using the extracted minimum cell voltage and the maximum cell voltage, a voltage difference between the minimum cell voltage and the maximum cell voltage (hereinafter referred to as a cell voltage difference) is calculated by the following formula (3). According to 4), it is determined whether or not the voltage difference between the minimum cell voltage and the maximum cell voltage is within a first specified value that is a threshold value of the voltage variation of the battery cells in the battery block 401.
Maximum cell voltage-minimum cell voltage = cell voltage difference (3)
Cell voltage difference ≦ first specified value (4)
Then, as a result of the determination using Expression (4), the first variation determination unit 409 determines that the voltage of the battery cell included in the battery block 401 is higher when the cell voltage difference of the battery block 401 is greater than the first specified value. Judge that it is scattered. Then, the first variation determination unit 409 outputs a signal (hereinafter referred to as a first variation signal) indicating that the cell voltage difference of the battery block 401 is larger than a specified value to the first switching control unit 410. . Further, the first variation signal includes block identification information for identifying the battery block. The first variation signal may further include the voltage values of the four battery cells. The first variation determination unit 409 also calculates a cell voltage difference for the battery blocks 402 and 403 using Equation (3), and whether or not the cell voltage difference is greater than the first specified value using Equation (4). Determine whether. Then, the first variation determination unit 409 transmits a first variation signal indicating whether or not the cell voltage difference between the battery blocks 402 and 403 is larger than a specified value to the first switching control unit 410. Output to the unit 410. Note that when the first variation determination unit 409 is realized by a circuit, for example, a comparator or the like may be used.

  The first switching control unit 410 is realized as a partial function of the main control unit 408. When the first variation signal is input from the first variation determination unit 409, the first switching control unit 410 receives all the voltages of the battery block corresponding to the block identification information included in the first variation signal. A measurement value is acquired from the measurement unit. For example, when the block identification information indicates the battery block 401, the first switching control unit 410 acquires the measurement values of the respective voltage measurement units connected to the battery block 401, and the four battery cells included in the battery block 401 are obtained. Compare the voltages. Then, the first switching control unit 410 controls the three balance circuits 112 included in the first balance circuit 404 so as to move the charge from the battery cell having a high voltage to the battery cell having a low voltage. Specifically, the same control as the balance operation described with reference to FIG. 3 is performed on each balance circuit 112 included in the first balance circuit 404. Although the case where the block identification information indicates the battery block 401 has been described, even when the block identification information indicates the battery blocks 402 and 403, the voltage of the corresponding battery cell may be acquired and the same control may be performed. . Further, when the first switching control unit 410 is realized by a circuit, for example, a comparator and an oscillator may be used.

  The block voltage calculation unit 411 is realized as a partial function of the main control unit 408. And the block voltage calculation part 411 acquires the voltage value of all the battery cells which an assembled battery has from each voltage measurement part which is not shown in figure. Further, the voltage of the battery block 401 is calculated by adding all the voltages of the battery cells included in the battery block 401. Similarly, the voltage of the battery block 402 and the voltage of the battery block 403 are calculated. Then, the calculated voltages of the battery blocks 401 to 403 are output to the second variation determination unit 412. When the block voltage calculation unit 411 is realized by a circuit, for example, an adder or the like may be used. In addition, the block voltage calculation unit 411 is connected to all voltage measurement units connected in parallel to each battery cell by signal lines.

The second variation determination unit 412 is realized as a partial function of the main control unit 408. Then, the voltages of the battery blocks 401 to 403 calculated by the block voltage calculation unit 411 are acquired, respectively, and the minimum voltage (hereinafter referred to as the minimum block voltage) among the acquired voltages of the battery blocks 401 to 403 is the maximum. The voltage (hereinafter referred to as the maximum block voltage) is extracted. Then, using the extracted minimum block voltage and maximum block voltage, a voltage difference between the minimum block voltage and the maximum block voltage (hereinafter referred to as a block voltage difference) is calculated by the following formula (5). According to 6), it is determined whether or not the voltage difference between the minimum block voltage and the maximum block voltage is within a second specified value that is a threshold value of voltage variation of the battery blocks 401 to 403 included in the assembled battery.
Maximum block voltage-minimum block voltage = block voltage difference (5)
Block voltage difference ≤ second specified value (6)
Then, as a result of determination using Expression (6), the second variation determination unit 412 determines that the voltage of the battery blocks 401 to 403 included in the assembled battery when the block voltage difference of the assembled battery is greater than the second specified value. Judge that it is scattered. Then, the second variation determination unit 412 outputs a signal (hereinafter referred to as a second variation signal) indicating that the block voltage difference of the assembled battery is larger than the specified value to the second variation determination unit 412. The second variation signal may include the voltage values of the battery blocks 401 to 403. When the second variation determination unit 412 is realized by a circuit, for example, a comparator may be used.

  The second switching control unit 413 is realized as a partial function of the main control unit 408. When the second variation signal is input from the second variation determination unit 412, the second switching control unit 413 acquires the voltages of the battery blocks 401 to 403 from the block voltage calculation unit 411. In addition, the second switching control unit 413 compares the acquired voltages of the battery blocks 401 to 403. Then, the second switching control unit 413 controls the two balance circuits 112 included in the second balance circuit 407 so that the charges are moved from the battery block having a high voltage to the battery block having a low voltage. The specific control method is the same as the control in which the voltage of the battery cell in the balance operation described with reference to FIG. 3 is replaced with the voltage of the battery block. That is, control is performed such that a battery block having a high voltage is switched and then a battery block having a low voltage is switched. Note that when the second switching control unit 413 is realized by a circuit, for example, a comparator and an oscillator may be used.

The storage unit 111 has the same configuration as the storage unit 111 illustrated in FIG. Then, the first specified value used in the first variation determination unit 409 and the second specified value used in the second variation determination unit 412 are stored. Similar to the specified values described with reference to FIG. 2, the first specified value and the second specified value are appropriately determined according to the characteristics of the battery used by the user. As an example, the first specified value and the second specified value differ depending on the characteristics of the battery cell used and the accuracy required in the voltage equalization of the battery cell, but for example, several tens to several hundred mV Is set.
<Operation of voltage equalization control>
Next, the voltage equalization control operation of the embodiment will be described.

In the following description, as shown in FIG. 4, there are four battery cells that form each battery block and three battery blocks that form an assembled battery.
FIG. 5 is an activity diagram illustrating a voltage equalization processing procedure according to the embodiment.

  The voltage equalization apparatus 400 is configured to perform voltage equalization control when a signal for turning on voltage equalization control is input by a user or an input unit (not shown) of the main control unit 408 or when an ignition switch is turned off. To start.

  Then, the main control unit 408 equalizes the voltages of the four battery cells included in each battery block (S501), equalizes the voltages of the three battery blocks included in the assembled battery (S502), and the first balance circuit. 404 to 406 and the balance operation stop determination (S503) of the second balance circuit 407 are executed simultaneously. In S503, as long as any one or more of the first balance circuit and the second balance circuit are in operation, the determination in S503 is repeated (in operation in S503).

  Then, the main control unit 408 finishes the voltage equalization of the battery cells in S501 and the voltage equalization of the battery block in S502, and the balance operation of the first balance circuit and the second balance circuit is performed in S503. If it determines with having stopped (it stops in S503), it will be determined whether the voltage of the battery cell which forms the battery blocks 401-403 was equalized (S504).

  In S504, when it is determined that there is a battery block in which the voltage of the battery cell is not equalized among the battery blocks 401 to 403 (the battery cell voltage varies in S504), the process of S501 is performed. Run.

  In S504, when the voltage of the battery cell included in each of the battery blocks 401 to 403 is equalized (in S504, the voltage of the battery cell is equalized), the main control unit 408 determines that the voltage of the battery blocks 401 to 403 is It is determined whether or not equalization is performed (S505).

  In S505, when it is determined that the voltages of the battery blocks 401 to 403 forming the assembled battery are not equalized (in S505, the voltages of the battery blocks vary), the main control unit 408 performs the process of S502. Run.

  If it is determined in S505 that the voltages of the battery blocks 401 to 403 forming the assembled battery have been equalized (in S505, the voltages of the battery blocks are equalized), the main control unit 408 ends the voltage equalization control. .

As described above, by operating the voltage equalization apparatus 400, it is possible to equalize the voltages of all the battery cells. Moreover, although it demonstrated that the process of S501-S503 was performed simultaneously, you may perform the process of S501 and the process of S502 in order. In that case, the process of S502 may be performed after the process of S501 is completed, or the process of S501 may be performed after the process of S502 is completed. Further, the processing of S503 may be performed after the processing of S501 and the processing of S502 are completed. S503 to S505 are referred to as voltage equalization determination processing.
<Battery cell voltage equalization processing procedure>
Next, the battery cell voltage equalization process in S501 will be described in detail.

  FIG. 6 is a flowchart showing the voltage equalization processing procedure of the battery cell according to the embodiment. Moreover, FIG. 9 is explanatory drawing which shows the change of the voltage of the battery cell at the time of the voltage equalization process which concerns on embodiment. In FIG. 9, the battery cells forming the battery block 401 shown in FIG. 4 are the cells 1 to 4, the battery cells forming the battery block 402 are the cells 5 to 8, and the battery block 403. The formed battery cells are designated as cell 9 to cell 12.

  The main control unit 408 of the voltage equalization apparatus 400 receives a signal for turning on voltage equalization control by a user using an input unit (not shown) of the main control unit 408, or when an ignition switch is turned off. Then, the voltage equalization process is started. In addition, the charge amount (voltage) of each battery cell of the battery blocks 401-403 at this time shall each vary as shown in [1] of FIG.

First, the main control unit 408 causes the voltage measurement unit connected to each battery cell to measure the voltages of all the battery cells constituting the assembled battery (S601).
And the 1st variation determination part 409 of the main-control part 408 calculates a cell voltage difference about each of the battery blocks 401-403 by acquiring a measured value from each voltage measurement part, and substituting into Formula (3). (S602).

  Also, the first variation determination unit 409 uses the equation (4) for each of the battery blocks 401 to 403 to calculate the cell voltage difference calculated in S602 and the first specified value stored in the storage unit 111. Compare. Then, the first variation determination unit 409 determines whether there is a battery block having a cell voltage difference larger than the first specified value (S603).

  If it is determined in S603 that there is no battery block having a cell voltage difference larger than the first specified value (No in S603), the main control unit 408 does not need to perform voltage equalization processing of the battery cells. The battery cell voltage equalization process is terminated.

  In S603, when it is determined that there is a battery block whose cell voltage difference is larger than the second specified value (Yes in S603), the first variation determination unit 409 includes the first variation including the identifier of the battery block. The signal is output to the first switching control unit 410. Then, when the first variation signal is input, the first switching control unit 410 acquires an identifier, and is connected to a battery block having a cell voltage difference larger than the first specified value based on the identifier. The balance operation is performed on the first balance circuit (S604).

  Then, the main control unit 408 controls the plurality of voltage measurement units to measure the voltage of the battery cell that forms each battery block in which the first balance circuit is performing the balancing operation (S605). Further, the first variation determination unit 409 obtains the voltage of the battery cell measured in S605, and uses the equation (3), the cell voltage that forms each battery block in which the first balance circuit is performing the balancing operation. The difference is calculated (S606).

  Then, the first variation determination unit 409 uses the equation (4) to determine the battery block in which the cell voltage difference is equal to or less than the first specified value among the battery blocks in which the first balance circuit is performing the balancing operation. It is determined whether or not there is (S607).

  In S607, when it is determined that there is no battery block whose cell voltage difference is equal to or less than the first specified value (No in S607), the first variation determination unit 409 executes the process of S609.

  In S607, when it is determined that there is a battery block whose cell voltage difference is equal to or less than the first specified value (Yes in S607), the first switching control unit 410 determines that the cell voltage difference is the first specified value. The balance operation of the first balance circuit connected to the battery block which has become below is stopped (S608).

Then, the first variation determination unit 409 determines whether or not the cell voltage difference has become equal to or less than the first specified value in all battery blocks (S609).
As a result of the determination in S609, when there is a battery block whose cell voltage difference is not less than or equal to the first specified value (No in S609), the first variation determination unit 409 includes the identification number of the corresponding battery block. The first variation signal is output to the first switching control unit 410. And if the 1st variation signal is acquired, the 1st switching control part 410 will perform processing of S604.

  As a result of the determination in S609, when it is determined that the cell voltage difference has become equal to or smaller than the first specified value in all battery blocks (Yes in S609), the main control unit 408 ends the voltage equalization process of the battery cells. To do.

In addition, the charge amount (voltage) of each battery cell of the battery blocks 401-403 at this time is equalized, as shown in [2] of FIG. However, the voltages of the battery blocks 401 to 403 vary.
<Battery block voltage equalization processing procedure>
Next, the battery block voltage equalization processing in S502 will be described in detail.

FIG. 7 is a flowchart showing the voltage equalization processing procedure of the battery block according to the embodiment.
The main control unit 408 of the voltage equalization apparatus 400 receives a signal for turning on voltage equalization control by a user using an input unit (not shown) of the main control unit 408, or when an ignition switch is turned off. Then, the voltage equalization process of the battery blocks 401 to 403 is started. Note that the charge amounts (voltages) of the battery blocks 401 to 403 at this time vary as shown in [2] of FIG. The reason why the control is started from the state [2] in FIG. 9 is for simplification of the description, and the control is normally started from the state [1] in FIG.

The main control unit 408 of the voltage equalization apparatus 400 causes the voltage measurement unit connected to each battery cell to measure the voltages of all the battery cells constituting the assembled battery (S701).
And the block voltage calculation part 411 of the main control part 408 acquires the measured value of the voltage of all the battery cells, and calculates the voltage of the battery blocks 401-403 (S702).

  And the 2nd variation determination part 412 calculates the block voltage difference of an assembled battery by acquiring the voltage of the battery blocks 401-403 from the block voltage calculation part 411, and substituting into Formula (5) (S703). .

  In addition, the second variation determination unit 412 compares the block voltage difference of the assembled battery calculated using Expression (6) with the second specified value stored in the storage unit 111, and the block voltage difference is calculated. It is determined whether it is larger than the second specified value (S704).

  In S704, when it is determined that the block voltage difference is equal to or smaller than the second specified value (No in S704), the main control unit 408 determines that it is not necessary to perform the voltage equalization process on the battery blocks 401 to 403, The voltage equalization process of the battery blocks 401 to 403 is finished.

  When it is determined in S704 that the block voltage difference is larger than the second specified value (Yes in S704), the second variation determination unit 412 outputs the second variation signal to the second switching control unit 413. To do. Then, when the second variation signal is input, the second switching control unit 413 causes the second balance circuit to perform a balancing operation (S705).

Then, the main control unit 408 causes the voltage measurement unit connected to each battery cell to measure the voltages of all the battery cells constituting the assembled battery (S706).
Moreover, the block voltage calculation part 411 acquires the measured value of the voltage of all the battery cells, and calculates the voltage of the battery blocks 401-403 (S707).

  Then, the 2nd variation determination part 412 calculates the block voltage difference of an assembled battery by acquiring the voltage of the battery blocks 401-403 from the block voltage calculation part 411, and substituting into Formula (5) (S708). .

  Furthermore, the second variation determination unit 412 compares the block voltage difference of the assembled battery calculated using Expression (6) with the second specified value, and the block voltage difference becomes equal to or less than the second specified value. It is determined whether or not (S709).

If it is determined in S709 that the lock voltage difference is not equal to or smaller than the second specified value (No in S709), the main control unit 108 executes the process of S706.
In S709, when it is determined that the block voltage difference is equal to or smaller than the second specified value (Yes in S709), the second switching control unit 413 stops the balance operation of the second balance circuit 407 (S710). ). Then, the main control unit 408 ends the voltage equalization process of the battery block.

In addition, as shown in [3] of FIG. 9, each battery cell of the battery blocks 401-403 at this time and the charge amount (voltage) of the battery blocks 401-403 are each equalized.
<Voltage equalization determination processing>
Next, the voltage equalization determination process in S503 to 505 will be described in detail.

FIG. 8 is a flowchart illustrating the voltage equalization determination process according to the embodiment.
The main control unit 408 of the voltage equalization apparatus 400 receives a signal for turning on voltage equalization control by a user using an input unit (not shown) of the main control unit 408, or when an ignition switch is turned off. Then, the voltage equalization determination process for the battery cells and the battery blocks 401 to 403 is started.

The main control unit 408 inquires of the first switching control unit 410 whether or not the first balance circuits 404 to 406 are stopped (S801).
If the first balance circuit 404 to 406 includes the first balance circuit that is performing the balance operation (No in S801), the main control unit 408 ends the operations of all the first balance circuits. The operation of S801 is repeated until

  In addition, when the balance operation of the first balance circuits 404 to 406 is stopped (Yes in S801), the main control unit 408 causes the second switching control unit 413 to stop the second balance circuit 407. An inquiry is made as to whether or not (S802).

When the second balance circuit 407 is performing a balance operation (No in S802), the main control unit 408 repeats the operation of S802 until the operation of the second balance circuit is completed.
Further, when the balancing operation of the second balance circuit 407 is stopped (Yes in S802), the main control unit 408 connects the voltages of all the battery cells constituting the assembled battery to each battery cell. The voltage measuring unit is measured (S803).

  And the 1st variation determination part 409 calculates a cell voltage difference about each of the battery blocks 401-403 by acquiring a measured value from each voltage measurement part, and substituting into Formula (3) (S804).

  Further, the first variation determination unit 409 uses the equation (4) for each of the battery blocks 401 to 403 to calculate the cell voltage difference calculated in S804 and the first specified value stored in the storage unit 111. Compare. Then, the first variation determination unit 409 determines whether or not the cell voltage difference is less than or equal to the first specified value in all battery blocks (S805).

  In S805, when it is determined that there is a battery block whose cell voltage difference is larger than the second specified value (No in S805), the first variation determination unit 409 includes the first variation including the identifier of the battery block. The signal is output to the first switching control unit 410. Then, when the first variation signal is input, the first switching control unit 410 executes the process of S604.

  In S805, when it is determined that the cell voltage difference is less than or equal to the first specified value in all battery blocks (Yes in S805), the first variation determination unit 409 correctly performs the battery cell voltage equalization process. It is determined that the process has ended.

Then, the block voltage calculation part 411 of the main control part 408 acquires the measured value of the voltage of all the battery cells, and calculates the voltage of the battery blocks 401-403 (S806).
And the 2nd variation determination part 412 calculates the block voltage difference of an assembled battery by acquiring the voltage of the battery blocks 401-403 from the block voltage calculation part 411, and substituting into Formula (5) (S807). .

  Further, the second variation determination unit 412 compares the block voltage difference of the assembled battery calculated using the equation (6) with the second specified value stored in the storage unit 111, and the block voltage difference is calculated. It is determined whether or not the value is equal to or less than the second specified value (S808).

  When it is determined in S808 that the block voltage difference is larger than the second specified value (No in S808), the second variation determination unit 412 outputs the second variation signal to the second switching control unit 413. To do. Then, when the second variation signal is input, the second switching control unit 413 performs the process of S705.

  As a result of the determination in S808, when it is determined that the block voltage difference is equal to or smaller than the second specified value (Yes in S704), the second variation determination unit 412 has normal voltage equalization processing of the battery blocks 401 to 403. It is determined that the process has ended.

  As described above, the active type voltage equalization apparatus according to the embodiment includes the first balance circuit that equalizes the voltages of the plurality of battery cells that form each battery block, and the plurality that forms the assembled battery. And a second balance circuit for equalizing the voltage of the battery block. And when equalizing the voltage of all the battery cells which form an assembled battery, a voltage equalization apparatus operates a 1st balance circuit and a 2nd balance circuit simultaneously. Thereby, the balance time of the balance circuit using the active method can be shortened, and the energy efficiency of the voltage equalization control can be improved.

  The active voltage equalization apparatus according to the embodiment includes a plurality of battery cells that form each battery block after the balance operation of the first balance circuit and the balance operation of the second balance circuit are completed. It is determined whether the voltage and the voltages of the plurality of battery blocks forming the assembled battery are equalized. When the voltages of the plurality of battery cells forming each battery block or the voltages of the plurality of battery blocks forming the assembled battery are not equalized, the balancing operation of the first balance circuit or the second Execute the balance operation of the balance circuit. As a result, even when only one of the balance operation of the first balance circuit and the balance operation of the second balance circuit is operating, the voltage related to the balance circuit that is not operating varies. Variation can be detected and equalized. More specifically, when the balance operation of the second balance circuit continues after the end of the balance operation of the first balance circuit, a plurality of batteries forming each battery block by the balance operation of the second balance circuit It affects the cell voltage and may vary. In this case, after the balance operation of the first balance circuit and the balance operation of the second balance circuit are finished, voltage variations of a plurality of battery cells forming each battery block are detected, and the first balance is again detected. The circuit was configured to perform a balancing operation. Thereby, since the dispersion | variation in the voltage of the some battery cell which forms each battery block is equalized again, the fall of the precision of voltage equalization can be suppressed.

  In the above description, the first balance circuit and the second balance circuit are provided, but in addition to this, a plurality of assembled batteries in which a plurality of battery blocks are connected in series are connected in series. A third balance circuit for equalizing the voltages may be provided. In this case, the main control unit 408 includes a third switching control unit and a third variation determination unit. Furthermore, you may provide the 4th balance circuit which connects the battery group which connected the some assembled battery in series, connects several series, and equalizes the voltage of the battery group. In this case, the main control unit 408 includes a fourth switching control unit and a fourth variation determination unit. In this way, by appropriately configuring a multi-stage balance circuit, even when the number of battery cells forming the assembled battery is increased, the charge is transferred when the charge is transferred between the battery cells separated in the balance operation. The number of circuits to be reduced can be reduced. Therefore, the balance time can be shortened and the energy efficiency of the voltage equalization control can be improved. The configurations and operations of the third variation determination unit, the third switching control unit, the fourth variation determination unit, and the fourth switching control unit are the first variation determination unit and the first variation determination unit, respectively. It is the same as the switching control unit. However, the target for voltage equalization control is changed between battery cells, between assembled batteries, and between battery groups.

DESCRIPTION OF SYMBOLS 100 Voltage equalization apparatus 101,102 Battery cell 103,104 Switch element 105 Coil 106,107 Voltage measurement part 108 Main control part 109 Dispersion judgment part 110 Switching control part 111 Storage part 112 Balance circuit 201 Specified value table 202 Graph 300 Balance operation Graph 400 Voltage equalization device 401-403 Battery block 404-406 First balance circuit 407 Second balance circuit 408 Main control unit 409 Variation determination unit 410 Switching control unit 411 Block voltage calculation unit 412 Variation determination unit 413 Switching control unit

Claims (16)

A battery block in which a number of battery blocks in which a number of battery cells (a is a natural number of 2 or more) are connected in series;
The n-th (n is a natural number from 1 to a-1) battery cell, the (n + 1) -th battery cell, the 2n-1 switch element and the 2n switch element connected in series in each battery block. N-1 coil is connected between the nth battery cell and the (n + 1) th battery cell, and between the 2n-1 switch element and the 2nth switch element, a-1 First balance circuits,
The m-th (m is a natural number from 1 to b-1) battery block, the (m + 1) -th battery block, and the 2m-1 and 2m-th switch elements connected in series are connected in parallel. B-1 pieces connected, and the m-th coil is connected between the m-th battery block and the m + 1-th battery block, and between the 2m-1 switch element and the 2m-th switch element. A second balance circuit of
A first switching control unit configured to switch the switch elements of the first balance circuit so that the voltages of adjacent battery cells of the a battery cells forming the battery block are equalized;
A second switching control unit that switches the switch elements of the second balance circuit so that the voltages of the adjacent battery blocks of the b battery blocks forming the assembled battery are equalized;
A voltage equalizing apparatus comprising: A voltage measuring unit that measures the voltage of each of the a × b battery cells;
The voltage value of the a × b battery cells measured by the voltage measuring unit is obtained, and the voltage of the a battery cells forming the battery block for each battery block forms the battery block. A first variation determination unit that determines whether or not the variation varies from a first specified value that is a threshold value of variation in voltage of battery cells;
With
The first switching control unit includes:
As a result of the determination by the first variation determination unit, when there is a battery block in which the voltage of the a battery cells forming the battery block varies from the first specified value, the battery block is formed. 2. The voltage equalization apparatus according to claim 1, wherein the switch elements of the first balance circuit are switched so that the voltages of adjacent battery cells of the a battery cells are equalized. A voltage measuring unit that measures the voltage of each of the a × b battery cells;
The voltage value of the a × b battery cells measured by the voltage measuring unit is obtained, and the voltage of the battery block obtained by adding the voltage of the a battery cells forming the battery block is added for each battery block. A block voltage calculator for calculating,
The voltage of the battery block calculated by the block voltage calculation unit is acquired, and the voltage of the b battery blocks varies from a second specified value which is a threshold value of voltage variation of the battery blocks forming the assembled battery. A second variation determination unit for determining whether or not
With
The second switching controller is
As a result of the determination by the second variation determination unit, when the voltages of the b battery blocks vary more than the second specified value, the voltages of the adjacent battery blocks of the b battery blocks are equal. The voltage equalization apparatus according to claim 1, wherein the switching element of the second balance circuit is switched so as to be equalized. A voltage measuring unit that measures the voltage of each of the a × b battery cells;
The voltage value of the a × b battery cells measured by the voltage measuring unit is obtained, and the voltage of the a battery cells forming the battery block for each battery block forms the battery block. A first variation determination unit that determines whether or not the variation varies from a first specified value that is a threshold value of variation in voltage of battery cells;
The voltage value of the a × b battery cells measured by the voltage measuring unit is obtained, and the voltage of the battery block obtained by adding the voltage of the a battery cells forming the battery block is added for each battery block. A block voltage calculator for calculating,
The voltage of the battery block calculated by the block voltage calculation unit is acquired, and the voltage of the b battery blocks varies from a second specified value which is a threshold value of voltage variation of the battery blocks forming the assembled battery. A second variation determination unit for determining whether or not
With
The first switching control unit includes:
As a result of determination by the first variation determination unit, when there is a battery block in which the voltage of the a battery cells forming the battery block varies from the first specified value, the battery block is formed. switching the switch element of the first balance circuit so that the voltage between adjacent battery cells of a battery cells is equalized,
The second switching controller is
As a result of the determination by the second variation determination unit, when the voltages of the b battery blocks vary from the second specified value, the voltages of the battery blocks adjacent to the b battery blocks are equalized. The voltage equalizing apparatus according to claim 1, wherein the switching element of the second balance circuit is switched.   The first specified value specifies an upper limit value of a voltage difference between a battery cell showing the maximum voltage and a battery cell showing the minimum voltage among the a battery cells forming the battery block. The voltage equalizing apparatus according to claim 2, wherein the voltage equalizing apparatus is provided. The first variation determination unit includes a battery cell exhibiting a maximum voltage among the a battery cells forming the battery block when the switch element of the first balance circuit is switching; and Determining whether the voltage difference with the battery cell showing the minimum voltage is within the first specified value;
In the first variation determination unit, a voltage difference between a battery cell showing the maximum voltage and a battery cell showing the minimum voltage among the a battery cells forming the battery block is the first difference. 6. The voltage equalization according to claim 5, wherein the first switching control unit stops switching of the switch element of the first balance circuit when it is determined that the current value is within a predetermined value. apparatus.   The second specified value specifies an upper limit value of a voltage difference between the battery block showing the maximum voltage and the battery block showing the minimum voltage among the b battery blocks. The voltage equalizing apparatus according to claim 3 or 4. The second variation determination unit indicates a battery block indicating a maximum voltage and a minimum voltage among the b battery blocks when the switch element of the second balance circuit is switched. Determining whether the voltage difference with the battery block is within the second specified value;
In the second variation determination unit, a voltage difference between a battery block indicating the maximum voltage and a battery block indicating the minimum voltage among the b battery blocks is within the second specified value. The voltage equalization apparatus according to claim 7, wherein when it is determined that the second switching circuit is determined, the second switching control unit stops switching of the switch element of the second balance circuit.   The first switching control unit moves the charge between adjacent battery cells of a number of battery cells forming the battery block from a battery cell having a high voltage to a battery cell having a low voltage. The voltage equalization apparatus according to any one of claims 1 to 8, wherein the switching elements connected in parallel with matching battery cells are alternately switched.   The switch that is connected in parallel with the adjacent battery block so that the second switching control unit moves electric charge from the battery block having a high voltage to the battery block having a low voltage between the adjacent battery blocks. The voltage equalizing apparatus according to any one of claims 1 to 9, wherein the elements are alternately switched.   A control for equalizing voltages between adjacent battery cells of the a battery cells forming the battery block of the first switching control unit; and b battery blocks of the second switching control unit. The voltage equalization apparatus according to any one of claims 1 to 10, wherein the control for equalizing voltages between adjacent battery blocks is performed simultaneously.   The second switching control unit equalizes the voltage between the adjacent battery cells of the a battery cells forming the battery block, and then sets the voltage between the adjacent battery blocks of the b battery blocks. The voltage equalization apparatus according to claim 1, wherein control for equalization is performed.   The first switching control unit equalizes the voltages between the adjacent battery blocks of the b battery blocks, and then sets the voltage between the adjacent battery cells of the a battery cells forming the battery block. The voltage equalization apparatus according to claim 1, wherein control for equalization is performed. A control for equalizing voltages between adjacent battery cells of the a battery cells forming the battery block of the first switching control unit; and b battery blocks of the second switching control unit. When the control to equalize the voltages between adjacent battery blocks is finished and the first balance circuit and the second balance circuit are stopped,
The voltage measuring unit measures the voltage of each of the a × b battery cells,
The first variation determination unit acquires the voltage value of the a × b battery cells measured by the voltage measurement unit, and for each of the battery blocks, the battery block is formed for each of the a battery cells. Determining whether the voltage varies from the first specified value;
The first switching control unit has a battery block in which the voltage of the a battery cells forming the battery block varies from the first specified value as a result of the determination by the first variation determination unit. The switch element of the first balance circuit is switched so that the voltages of the adjacent battery cells of the a battery cells forming the battery block are equalized. The voltage equalizing apparatus according to any one of 13. A control for equalizing voltages between adjacent battery cells of the a battery cells forming the battery block of the first switching control unit; and b battery blocks of the second switching control unit. When the control to equalize the voltages between adjacent battery blocks is finished and the first balance circuit and the second balance circuit are stopped,
The voltage measuring unit measures the voltage of each of the a × b battery cells,
The block voltage calculation unit obtains the voltage value of the a × b battery cells measured by the voltage measurement unit, and calculates the voltage of the a battery cells forming the battery block for each battery block. Calculate the added battery block voltage,
The second variation determination unit acquires the voltage of the battery block calculated by the block voltage calculation unit, and the voltage of the b battery blocks is a threshold value of a variation in voltage of the battery blocks forming the assembled battery. It is determined whether or not there is a variation from the second specified value,
When the voltage of the b battery blocks varies more than the second specified value as a result of the determination by the second variation determination unit, the second switching control unit determines whether the b battery blocks The voltage equalization apparatus according to any one of claims 1 to 14, wherein the switch elements of the second balance circuit are switched so that voltages between adjacent battery blocks are equalized. A battery block in which a number (a is a natural number of 2 or more) battery cells connected in series, b (b is a natural number of 2 or more) battery modules connected in series, c batteries (c is a natural number of 2 or more) A group of batteries connected in series;
The n-th (n is a natural number from 1 to a-1) battery cell, the (n + 1) -th battery cell, the 2n-1 switch element and the 2n switch element connected in series in each battery block. N-1 coil is connected between the nth battery cell and the (n + 1) th battery cell, and between the 2n-1 switch element and the 2nth switch element, a-1 First balance circuits,
The m-th (m is a natural number from 1 to b-1) battery block, the (m + 1) -th battery block, and the 2m-1 and 2m-th switch elements connected in series are connected in parallel. B-1 pieces connected, and the m-th coil is connected between the m-th battery block and the m + 1-th battery block, and between the 2m-1 switch element and the 2m-th switch element. A second balance circuit of
The kth (k is a natural number from 1 to c-1) assembled battery, the (k + 1) th assembled battery, the 2k-1 switch element and the 2k switch element connected in series in the battery group. C-1 coils connected between the k-th assembled battery and the (k + 1) -th assembled battery and between the 2k-1 switch element and the 2k-th switch element. A third balance circuit of
A first switching control unit configured to switch the switch elements of the first balance circuit so that the voltages of adjacent battery cells of the a battery cells forming the battery block are equalized;
A second switching control unit that switches the switch elements of the second balance circuit so that the voltages of the adjacent battery blocks of the b battery blocks forming the assembled battery are equalized;
A third switching control unit that switches the switch elements of the third balance circuit so that the voltages of the adjacent assembled batteries of the c assembled batteries forming the battery group are equalized;
A voltage equalizing apparatus comprising: