JP5168176B2 - Battery pack capacity adjustment device - Google Patents

Description

  The present invention relates to a battery pack capacity adjustment device that reduces variations in the capacity of unit batteries that are one or a plurality of adjacent battery cells constituting the battery pack, as battery packs that are connected in series with battery cells.

  As this type of capacity adjustment device, for example, as seen in Patent Documents 1 and 2 below, battery cells constituting an assembled battery are grouped into a plurality of battery cells to form blocks, and each cell is divided into battery cells. Some have been provided with a dedicated integrated circuit that performs processing for reducing variations in voltage. The capacity adjusting device further includes a block voltage detecting means and a microcomputer, and performs a process of discharging a high voltage block using the microcomputer based on the detection result of the block voltage. Thereby, the capacity | capacitance of all the battery cells which comprise an assembled battery can be equalized.

  Further, as this type of capacity adjustment device, for example, as seen in Patent Document 3 below, an integrated circuit that performs a process of discharging the higher voltage of a pair of battery cells is provided, and voltage comparison is performed in each integrated circuit. It has also been proposed to share one of the target battery cells between adjacent integrated circuits. Also by this, the capacity | capacitance of all the battery cells which comprise an assembled battery can be equalized.

JP 2002-325370 A JP 2002-281687 A JP-A-8-55643

  By the way, in the capacity adjusting devices described in Patent Documents 1 and 2, the withstand voltage required for the block voltage detecting means becomes very high. For this reason, it is difficult to configure the block voltage detection means with an integrated circuit, and it is difficult to reduce the size of the capacity adjustment device. Moreover, since the equalization process between blocks is performed by the microcomputer, the calculation load of the microcomputer used for monitoring the state of the assembled battery increases. In particular, when a lithium secondary battery is used as an assembled battery, the calculation load of the microcomputer that issues a command to the integrated circuit is large due to the increase in the number of processes to be performed by the integrated circuit provided for each block. This problem is serious because it becomes a thing.

  Further, in the capacity adjustment device described in Patent Document 3, power is consumed for battery cells shared between adjacent integrated circuits because power is consumed by voltage comparison processing in each integrated circuit. For this reason, the voltage drop amount due to the internal resistance varies among the battery cells, and the accuracy of the voltage comparison is lowered. Further, the battery cell that consumes power in both of the adjacent integrated circuits and the battery cell that consumes power only in a single integrated circuit are different from each other. There is also a possibility that the variation in the capacity of the battery increases.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is one or a plurality of adjacent battery cells constituting the assembled battery with respect to the assembled battery as a series connection body of battery cells. It is an object of the present invention to provide a battery pack capacity adjustment device that can more appropriately reduce the variation in unit battery capacity.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

According to the first aspect of the present invention, there is provided an assembled battery as a series connection body of battery cells. In the adjustment device, the unit batteries constituting the assembled battery are grouped into a plurality of unit batteries adjacent to each other to form a block, and include state monitoring means corresponding to each of the plurality of blocks. At least a part of the monitoring means is a capacitor, a unit battery in the target block and a connection means for selectively connecting a part of the unit cells in the block adjacent to the target block to the capacitor, and the unit battery Operating means for operating the connecting means to charge the capacitor; and a unit power connected to the capacitor based on a charging voltage of the capacitor. A voltage detecting means for detecting a voltage of, and a reduction means for performing processing to reduce variation of the voltage of the unit batteries to each other based on the voltage detected by said voltage detecting means, the capacity adjusting device, the plurality of The voltage of each unit battery constituting each of the blocks is periodically detected, and in the plurality of cycles for detecting the voltage of the unit battery, the voltage of the part of unit batteries detected by the plurality of state monitoring means is detected. At least one of the voltage detection processes is performed in a state where the capacitor is precharged with the same polarity as that assumed when the capacitor is charged by the partial unit battery .

  In the said invention, at least one part of a state monitoring means has a function which detects the voltage of the unit cell of not only a target block but a part of adjacent block. For this reason, by performing the process of reducing the voltage variation based on the voltage detection result by each state monitoring means, it is possible to reduce the voltage variation of all the unit cells constituting the assembled battery, and thus all the unit cells. The variation in capacity can be reduced. In particular, in the above-described invention, since each state monitoring unit only detects the voltage of a part of unit cells of adjacent blocks, the required withstand voltage can be suitably suppressed. Furthermore, in the above invention, since the voltage of the unit battery is detected based on the charging voltage of the capacitor, the voltage of the unit battery when the current flowing from the unit battery to the capacitor side becomes zero can be detected. For this reason, in the voltage detection, it is possible to eliminate the influence of the voltage drop due to the current flowing from the unit battery to the voltage detection system.

  The at least one part may be the whole of the state monitoring means, but it is desirable that the number be one less than this.

Furthermore, in the above invention, periodic voltage detection is performed by performing at least one of the voltage detection processes of some unit batteries in a state where the capacitor is charged in advance with the same polarity as the assumed polarity. In a plurality of processing cycles, it is possible to suppress as much as possible the discharge amount of some unit cells from being particularly large.

  In addition, the number of times of detecting the voltage of the part of unit cells in a state where the capacitor is charged in advance in the same polarity as the polarity assumed when the capacitor is charged by the part of unit batteries, The voltage is detected by the single state monitoring means in a state where the capacitor is precharged with the same polarity as that assumed when the capacitor is charged by the unit battery whose voltage is detected by the single state monitoring means. It is desirable to set a value larger than the number of times (including zero) of detecting the voltage of the unit battery. In addition, the number of times of detecting the voltage of the part of unit cells in a state where the capacitor is charged in advance with the same polarity as the polarity assumed when the capacitor is charged by the part of unit batteries, It is desirable that the value exceeds half the number of periods of the plurality of periods.

In the invention of claim 2 and 3, wherein the state monitoring means of said at least one part is a voltage of a portion of the unit cell of the adjacent blocks in the same polarity which is assumed when applied to the capacitor A process of detecting a voltage of a unit battery in the adjacent block is performed in a state where the capacitor is charged by the unit battery in the target block.

  In the said invention, it can suppress as much as possible that the discharge amount of a part of unit cell increases especially by voltage detection processing.

According to a fourth and fifth aspect of the present invention , the operation means provided in the at least one part of the state monitoring means does not reverse the charge polarity when the part of unit cells are connected to the capacitor and is within the target block. When the unit battery is connected to the capacitor, the connection means is operated so that the charging polarity is reversed.

  In the said invention, it can suppress as much as possible that the discharge amount of a part of unit cell increases especially by voltage detection processing.

In the inventions according to claims 6 and 7 , the state monitoring means further includes a reset means for discharging the charge of the capacitor, and the reset means provided in the at least one part of the state monitoring means is provided in the target block. The unit battery is discharged when the capacitor is connected to the capacitor, and the capacitor is not discharged when the unit battery is connected to the capacitor. To do.

  In the said invention, it can suppress as much as possible that the discharge amount of a part of unit cell increases especially by voltage detection processing.

In the inventions according to claims 8 and 9 , in the state monitoring means, the connection means includes a part of unit cells in only one of the high potential side and the low potential side adjacent to the target block. The one having a function of selectively connecting to the capacitor and having the function of discharging the part of unit cells connectable by the connecting means is included.

  In the above invention, the state monitoring means including the reduction means having a function of discharging a part of unit cells connectable by the connection means is provided, so that the connection means is on the high potential side and the low potential side adjacent to the target block. While some of the unit cells in only one block are selectively connected to the capacitor, it is possible to reduce the capacity variation of all unit cells of the assembled battery.

  The at least one part of the state monitoring means is preferably the state monitoring means specified in the present invention.

In the inventions according to claims 10 and 11 , except for any one of the highest potential side and the lowest potential side of the state monitoring means, the connection means is a high adjacent to the target block. A part of the unit cells in which only a part of the unit cells in the block on either the potential side or the low potential side is selectively connected to the capacitor, and the reducing means can be connected by the connecting means. It has a function of discharging the battery.

  In the above invention, the state monitoring means other than the highest potential or the lowest potential is provided with a reducing means having a function of discharging the part of unit cells connectable by the connection means, so that the connection means is the target block. It is possible to reduce the capacity variation of all unit batteries of the assembled battery while selectively connecting a part of the unit batteries in only one block on either the high potential side or the low potential side to the capacitor. It becomes possible.

  The at least one state monitoring unit is a state monitoring unit other than the highest potential or the lowest potential here.

1 is a system configuration diagram according to a first embodiment. FIG. The circuit diagram which shows the circuit structure of the monitoring unit concerning the embodiment. The time chart which shows the voltage detection process concerning the embodiment. The circuit diagram which shows the circuit structure of the monitoring unit concerning 2nd Embodiment. The time chart which shows the voltage detection process concerning the embodiment. The circuit diagram which shows the circuit structure of the monitoring unit concerning 3rd Embodiment. The time chart which shows the voltage detection process concerning the embodiment.

(First embodiment)
Hereinafter, a first embodiment in which a battery pack capacity adjustment apparatus according to the present invention is applied to a capacity adjustment apparatus for a hybrid vehicle will be described with reference to the drawings.

  FIG. 1 shows a system configuration according to the present embodiment.

  As shown in the figure, the assembled battery 10 constitutes an in-vehicle high-voltage system and serves as a power source for a motor generator as an in-vehicle main machine. The assembled battery 10 is a series connection body of battery cells Chi (h = 1 to n, i = 1 to m). Here, the battery cell Chi is a lithium ion secondary battery. The assembled batteries 10 are grouped by m adjacent to each other to form a block. And the state monitoring means of the battery cell in each of these blocks is the monitoring units U1-Un. The monitoring units U <b> 1 to Un perform block state monitoring processing based on a command from the microcomputer (microcomputer 12) fetched via the interface 14, and output the result to the microcomputer 12 via the interface 14. Incidentally, the microcomputer 12 constitutes an in-vehicle low-voltage system, and the interface 14 includes an insulating means that insulates the in-vehicle high-voltage system from the in-vehicle low voltage system.

  FIG. 2 shows the configuration of the monitoring unit Uk (k = 1 to n−1). In FIG. 2, the number of battery cells in each block is represented as “8”.

  As shown in the figure, the monitoring unit Uk is a multiplexer that selectively connects the battery cells Ck1 to Ck8 in the corresponding block and the battery cell C (k + 1) 1 having the highest potential in the adjacent low potential side block to the flying capacitor 20. MPX, a differential amplifier circuit 22 that converts the voltage across the flying capacitor 20, and an analog-to-digital converter (A / D converter 24) that converts an analog signal output from the differential amplifier circuit 22 into a digital signal. I have. Here, the multiplexer MPX is flying the switching element Sf1 connecting the positive electrode side of the battery cell Ck1 and the flying capacitor 20, the negative electrode side of the battery cell Ckx (x = 1 to 7) and the positive electrode side of the battery cell Ck (x + 1). A switching element Sf (x + 1) connected to the capacitor 20 and a switching element Sf9 connecting the negative electrode side of the battery cell Ck8 and the flying capacitor 20 are provided. Here, the connection electrode with the flying capacitor 20 is different between the odd-numbered and even-numbered switching elements Sf to Sf9. The multiplexer MPX further includes a switching element Sf10 for connecting the negative electrode side of the battery cell C (k + 1) 1 to one terminal of the flying capacitor 20, and a switching for connecting the positive electrode side to the other terminal of the flying capacitor 20. And an element Sf11.

  According to such a configuration, by switching on two adjacent switching elements Sf1 to Sf9 constituting the multiplexer MPX, one battery cell is selected from the battery cells Ck1 to Ck8, and the flying capacitor 20 Can be connected to both ends. Further, by turning on the switching elements Sf10 and Sf11 constituting the multiplexer MPX, the battery cell C (k + 1) 1 can be selected and connected to both ends of the flying capacitor 20. After that, all the switching elements of the multiplexer MPX are turned off and then the switching elements Sr1 and Sr2 are turned on, so that both ends of the flying capacitor 20 are connected to the input terminals of the differential amplifier circuit 22, and from the differential amplifier circuit 22 An analog signal indicating the charging voltage of the flying capacitor 20 can be output. Incidentally, the differential amplifier circuit 22 is for adjusting the charging voltage of the flying capacitor 20 and the voltage range that can be input to the A / D converter 24. That is, for example, when the charging voltage of the flying capacitor 20 can be larger than the maximum value of the input possible voltage of the A / D converter 24, the differential amplifier circuit 22 is assumed to reduce and convert the charging voltage of the flying capacitor 20, Thereby, the same effect as that of expanding the dynamic range of the A / D converter 24 is obtained.

  The monitoring unit Uk is also provided with a discharge circuit for discharging the charges of the battery cells Ck1 to Ck8 and the battery cell C (k + 1) 1. That is, a series connection body of a switching element Swy and a resistor Ry is connected in parallel to both ends of the battery cell Cky (y = 1 to 8), and switching is performed on both ends of the battery cell C (k + 1) 1. A series connection body of the element Sw9 and the resistor R9 is connected in parallel.

  The monitoring unit Uk further includes a processing circuit 30. The processing circuit 30 has a function of performing overcharge detection processing for detecting whether or not at least one of the battery cells Ck1 to Ck8 of the corresponding block (target block) is excessively charged (overcharged state). . The processing circuit 30 has a function of performing an overdischarge detection process for detecting whether or not at least one of the battery cells Ck1 to Ck8 in the corresponding block is in an excessively discharged state (overdischarge state). Further, the processing circuit 30 has a function of performing an equalizing discharge process for reducing variations in voltage between the battery cells Ck1 to Ck8 in the corresponding block and the battery cell C (k + 1) 1 in the adjacent block.

  All of these processes are performed by operating the multiplexer MPX to apply the voltage of the battery cell to the flying capacitor 20 and capturing digital data (output of the A / D converter 24) relating to this applied voltage. is there. Incidentally, the equalizing discharge process can be performed by turning on one of the switching elements Sw1 to SW9 that is connected in parallel to a battery cell having a high voltage.

  The monitoring unit Un has the same configuration as that shown in FIG. 2 except that it does not include the switching elements Sf10, Sf11, Sw9 and the resistor R9.

  FIG. 3 shows a voltage detection processing method by the monitoring unit Uk.

  As shown in the figure, the voltage detection process is periodically performed with the process of detecting the voltage one by one in turn while shifting the battery cells to be voltage detected to those adjacent to each other in potential. At this time, the charging polarity of the flying capacitor 20 is basically reversed every time the voltage is detected. However, when the voltage of the battery cell C (k + 1) 1 is detected after the voltage of the battery cell Ck8 is detected, the charge polarity is not reversed. This is realized by setting the connection of the switching elements Sf10 and Sf11. By setting it as such, the electric charge of the battery cell consumed when performing the process which detects the said voltage in each monitoring unit U1-Un for 1 period can be made substantially equal. This is because in one cycle of the voltage detection, the number of processes for charging the flying capacitor 20 becomes equal for all battery cells while inverting the charging polarity of the flying capacitor 20. That is, in detecting the voltage of each battery cell, the battery cell needs to be charged until the flying capacitor 20 has the same voltage as its own voltage. However, the amount of charge consumed at this time is negligibly small when the polarity is not reversed by charging compared to the case where the polarity is reversed by charging. For this reason, by making the number of processes whose polarity is reversed by charging equal for all battery cells, the charge of the battery cells consumed when the process of detecting the voltage in each of the monitoring units U1 to Un is performed for one cycle is substantially reduced. Can be equal.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) In the monitoring unit Uk, the flying capacitor 20 was used to detect the voltages of some of the battery cells in the adjacent block as well as the target block. Thus, by providing the battery cell in which a voltage is detected redundantly by a plurality of monitoring units, it becomes possible to equalize the capacity of all the battery cells by the processing of each monitoring unit. Moreover, since each monitoring unit only detects the voltage of a part of the battery cells in the adjacent block, the withstand voltage required for the monitoring unit Uk can be suitably suppressed. Furthermore, since the voltage of the battery cell is detected based on the charging voltage of the flying capacitor 20, it is possible to detect the voltage of the battery cell when the current flowing from the battery cell to the flying capacitor 20 becomes zero. For this reason, in the voltage detection, the influence of the voltage drop due to the current flowing from the battery cell to the voltage detection system can be eliminated.

  (2) Among the battery cell voltage detections in which the voltage is redundantly detected by the plurality of monitoring units in one cycle of the voltage detection process for periodically detecting the voltage of each battery cell constituting each of the plurality of blocks For one, the charging polarity of the flying capacitor 20 was not reversed. Thereby, it can suppress as much as possible that the discharge amount of a one part battery cell increases especially in one period of a periodic voltage detection process.

  (3) When connecting the battery cell in the corresponding block to the flying capacitor 20, the charge polarity is reversed, and when connecting the battery cell C (k + 1) 1 of the adjacent block to the flying capacitor 20, the charge polarity Was not reversed. Thereby, it can suppress as much as possible that the discharge amount of the battery cell C (k + 1) of an adjacent block increases especially by voltage detection processing.

  (4) The monitoring units Uk excluding the lowest potential monitoring unit Un have not only the voltage detection function of the battery cell C (k + 1) 1 in the adjacent low potential side block but also the discharge function thereof. As a result, the monitoring unit Uk only has the voltage detection function of the battery cell C (k + 1) 1 in the block on the low potential side, and thus it is possible to reduce the capacity variation of all the battery cells of the assembled battery 10.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 4 shows the configuration of the monitoring unit Uk according to the present embodiment. In FIG. 4, members corresponding to those shown in FIG. 2 are given the same reference numerals for convenience.

  As shown in the figure, in the present embodiment, the switching element Sfya for connecting the positive electrode of each battery cell Cky (1-8) to one terminal of the flying capacitor 20 and the negative electrode to the other terminal of the flying capacitor 20. And a switching element Sfyb for connection. In addition, a switching element Sf9a that connects the positive electrode of the battery cell C (k + 1) 1 of the adjacent block to one terminal of the flying capacitor 20 and a switching element Sf9b that connects the negative electrode to the other terminal of the flying capacitor 20 are provided. Yes. Thereby, the charging polarity of the flying capacitor 20 by each battery cell can be made the same by turning on the pair of switching elements Sfya and Sfyb and the switching elements Sf9a and Sf9b.

  However, in detecting the voltage, it is convenient to detect the change in charge of the flying capacitor 20 when detecting the disconnection abnormality of the multiplexer MPX or the like. Therefore, in the present embodiment, a reset unit that discharges the electric charge of the flying capacitor 20 is provided. Specifically, a series connection body of the switching element Sd and the resistor Rd is connected in parallel to the flying capacitor 20.

  FIG. 5 shows a voltage detection processing method by the monitoring unit Uk.

  As shown in the figure, the voltage detection process is periodically performed with the process of detecting the voltage one by one in turn while shifting the battery cells to be voltage detected to those adjacent to each other in potential. At this time, the charging polarity of the flying capacitor 20 is not always reversed. However, basically, prior to charging of the flying capacitor 20 by the battery cell, the switching element Sd is turned on in order to reset the charged amount of the flying capacitor 20. Thus, when the charging voltage of the flying capacitor 20 does not increase, it can be considered that the multiplexer MPX or the like is abnormal. In such processing, the amount of electricity stored in the flying capacitor 20 is not initialized only when the flying capacitor 20 is charged by the battery cell C (k + 1) 1 in the adjacent block. Also by this, the electric charge of the battery cell consumed when performing the said voltage detection process in 1 period in each monitoring unit U1-Un can be made substantially equal.

  According to this embodiment described above, in addition to the effects (1), (3), and (4) of the first embodiment, the following effects can be obtained.

  (5) When connecting the battery cells Ck1 to Ck8 in the target block to the flying capacitor 20, the charging charge of the flying capacitor 20 is discharged, and the battery cell C (k + 1) 1 of the adjacent block is used as the flying capacitor 20. When connecting, the flying capacitor 20 was not discharged. Thereby, it can suppress as much as possible that the discharge amount of battery cell C (k + 1) 1 of an adjacent block increases especially by voltage detection processing.

(Third embodiment)
Hereinafter, the third embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 6 shows the configuration of the monitoring unit Uk according to the present embodiment. In FIG. 6, members corresponding to those shown in FIG. 2 are given the same reference numerals for convenience.

  As shown in the drawing, in the present embodiment, a switching element for connecting the positive electrode of the battery cell C (k + 1) 1 of the adjacent block to the flying capacitor 20 and the negative electrode of the battery cell Ck8 are connected to the flying capacitor 20. The switching element was shared as the switching element Sf9. In this case, the charging polarity of the flying capacitor 20 by the battery cell Ck8 is opposite to the charging polarity of the flying capacitor 20 by the battery cell C (k + 1) 1.

  FIG. 7 shows a voltage detection processing method by the monitoring unit Uk.

  As shown in the drawing, the voltage detection processing according to the present embodiment is performed by setting the processing for detecting voltages in the order of battery cells Ck8, Ck7, Ck6, Ck5, Ck4, Ck3, Ck2, Ck1, and C (k + 1) 1 as one cycle. Performed periodically. Thereby, the charging polarity of the flying capacitor 20 is basically reversed every time the voltage is detected, but when the voltage of the battery cell C (k + 1) 1 is detected after the voltage of the battery cell Ck1 is detected, Does not reverse.

  According to the present embodiment described above, in addition to the effects according to the above (1) to (4) of the first embodiment, the following effects can be further obtained.

  (6) The switching element for connecting the positive electrode of the battery cell C8 (k + 1) to the flying capacitor 20 and the switching element for connecting the negative electrode of the battery cell Ck8 to the flying capacitor 20 are shared. Thereby, the number of parts can be reduced.

  (7) Battery cells adjacent to each other in potential except that the number of battery cells in the block is an even number and the voltage of the battery cell C8 (k + 1) is detected next to the battery cell farthest from the battery cell C8 (k + 1) The voltage was detected sequentially. Thereby, the effect according to said (2) of said 1st Embodiment and (3) can be acquired.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  At least one voltage detection process among the voltage detection processes of the battery cell C (k + 1) 1 in which voltage is detected by both of the adjacent monitoring units Uk and U (k + 1) in one cycle of the battery cell voltage detection process. Is not limited to those exemplified in the above embodiments as a method of performing the charging in a state where the flying capacitor 20 is charged in advance with the same polarity as the charging polarity of the battery cell C (k + 1) 1. For example, in the third embodiment, the voltage detection of the battery cell C (k + 1) 1 in the monitoring unit Uk is performed in a state where the flying capacitor 20 is charged with the opposite polarity to the charging polarity thereby, and the monitoring unit U (k + 1) The voltage detection of the battery cell C (k + 1) 1 in) may be performed in a state where the flying capacitor 20 is charged with the same polarity as the charging polarity. This can be realized by changing the voltage detection order of the battery cell Ck8 and the battery cell C (k + 1) 1 in the voltage detection process shown in FIG. In this case, only the number of battery cells in the block corresponding to the monitoring unit Un is set to an odd number, and the number of battery cells in the remaining blocks is set to an even number, so that the flying capacitor 20 is charged with reverse polarity in the voltage detection cycle. In this state, the number of times of voltage detection can be made the same for all cells.

  In each of the above embodiments, the monitoring unit Uk (k = 1 to n−1) detects the voltage of the battery cell C (k + 1) 1 of the target block of the adjacent low potential side monitoring unit U (k + 1), and Although this is provided with the function to discharge, it is not restricted to this. For example, the monitoring unit Uj (j = 2 to n) detects the voltage of the battery cell C (j−1) 1 of the target block of the adjacent high potential side monitoring unit U (j−1) and discharges this. It may be configured to have a function to perform. Further, the monitoring units U1, U2,... U (x-1) are configured to have a function of detecting the voltage of the battery cell of the target block of the adjacent monitoring unit on the low potential side and a function of discharging this, The monitoring units U (x + 1),... Un may be configured to have a function of detecting the voltage of the battery cell of the target block of the adjacent high-potential side monitoring unit and a function of discharging this.

  In each of the above embodiments, an example in which the voltage detection process is devised so as not to increase the amount of electric charge discharged from the battery cell C (k + 1) 1 is shown. In this case, the battery cell C (k + 1) 1 is used in the monitoring unit Uk. It is impossible to detect the presence or absence of disconnection of the path connecting the flying capacitor 20 based on the voltage change of the flying capacitor 20. In order to avoid this, for example, in the first embodiment, the voltage detection order of the battery cell Ck8 and the battery cell C (k + 1) 1 may be switched at a rate of once every plural times. Here, by sufficiently increasing the number of times, it is possible to suitably suppress an excessive increase in the discharge amount of the battery cell C (k + 1) 1.

  -As a monitoring unit, it is not restricted to what has the function to discharge the battery cell of the object block of an adjacent monitoring unit. For example, you may make it have the function to detect the voltage of the one part battery cell in the object block of all the monitoring units which adjoin. This is because, in each of the above embodiments, the voltages of some of the battery cells of the target block of each of the monitoring units U2, U3,. This is realized by changing the monitoring unit Un to have a function of detecting the voltage of a part of the battery cells of the target block of the adjacent monitoring unit on the high potential side. be able to.

  In each of the above embodiments, the process of reducing the voltage variation between the battery cells in the block is performed. However, the present invention is not limited to this. For example, the process of reducing the voltage variation between a pair of adjacent battery cells may be performed. .

  In each of the above embodiments, when the charging voltage of the flying capacitor 20 is an appropriate value for the input voltage range of the A / D converter 24, the differential amplifier circuit 22 may be omitted.

  -As a battery cell, not only a lithium secondary battery but a nickel-hydrogen secondary battery etc. may be sufficient. Further, the fuel cell is not limited to the secondary battery.

  In each of the above embodiments, the present invention is applied to a hybrid vehicle. However, the present invention is not limited to this, and the present invention may be applied to an electric vehicle or the like not equipped with an internal combustion engine.

  DESCRIPTION OF SYMBOLS 10 ... Battery pack, 12 ... Microcomputer, 14 ... Interface, 20 ... Flying capacitor, 22 ... Differential amplifier circuit, 30 ... Processing circuit, U1-Un ... Monitoring unit (one embodiment of a state monitoring means).

Claims (11)

About the assembled battery as a series connection body of battery cells, in the capacity adjustment device of the assembled battery for reducing the variation in the capacity of the unit battery that is one or a plurality of adjacent battery cells constituting the assembled battery,
Unit batteries constituting the assembled battery are grouped into a plurality of unit batteries adjacent to each other to form a block,
A state monitoring unit corresponding to each of the plurality of blocks;
At least a part of the state monitoring means includes a capacitor, a unit battery in the target block and a connection means for selectively connecting a part of the unit cells in the block adjacent to the target block to the capacitor, and the unit battery. Operating means for operating the connecting means to charge the capacitor, voltage detecting means for detecting a voltage of a unit cell connected to the capacitor based on a charging voltage of the capacitor, and detected by the voltage detecting means Reduction means for performing a process of reducing the variation in voltage between the unit cells based on the voltage ,
The capacity adjusting device periodically detects the voltage of each unit battery constituting each of the plurality of blocks.
In a plurality of cycles for detecting the voltage of the unit battery, at least one of the processes for detecting the voltage of the part of unit cells detected by a plurality of state monitoring means, A capacity adjustment device for an assembled battery, which is performed in a state where the capacitor is charged in advance with the same polarity as that assumed when charging . The at least one part of the state monitoring means may be configured such that the unit cell in the target block has the same polarity as the polarity assumed when the voltage of a part of unit cells in the adjacent block is applied to the capacitor. while it is charging a battery pack capacity adjustment apparatus according to claim 1 Symbol placement and performs a process of detecting a voltage of the unit cell of the adjacent block. About the assembled battery as a series connection body of battery cells, in the capacity adjustment device of the assembled battery for reducing the variation in the capacity of the unit battery that is one or a plurality of adjacent battery cells constituting the assembled battery,
Unit batteries constituting the assembled battery are grouped into a plurality of unit batteries adjacent to each other to form a block,
A state monitoring unit corresponding to each of the plurality of blocks;
At least a part of the state monitoring means includes a capacitor, a unit battery in the target block and a connection means for selectively connecting a part of the unit cells in the block adjacent to the target block to the capacitor, and the unit battery. Operating means for operating the connecting means to charge the capacitor, voltage detecting means for detecting a voltage of a unit cell connected to the capacitor based on a charging voltage of the capacitor, and detected by the voltage detecting means Reduction means for performing a process of reducing the variation in voltage between the unit cells based on the voltage,
The at least one part of the state monitoring means may be configured such that the unit cell in the target block has the same polarity as the polarity assumed when the voltage of a part of unit cells in the adjacent block is applied to the capacitor. The battery pack capacity adjustment device is characterized by performing a process of detecting the voltage of the unit battery in the adjacent block while the battery is charged.   The operating means provided in the at least one part of the state monitoring means is configured such that when connecting some of the unit cells to the capacitor, the charging polarity is not reversed and the unit cells in the target block are connected to the capacitor. The battery pack capacity adjustment device according to any one of claims 1 to 3, wherein the connection means is operated so that the charging polarity is reversed. About the assembled battery as a series connection body of battery cells, in the capacity adjustment device of the assembled battery for reducing the variation in the capacity of the unit battery that is one or a plurality of adjacent battery cells constituting the assembled battery,
Unit batteries constituting the assembled battery are grouped into a plurality of unit batteries adjacent to each other to form a block,
A state monitoring unit corresponding to each of the plurality of blocks;
At least a part of the state monitoring means includes a capacitor, a unit battery in the target block and a connection means for selectively connecting a part of the unit cells in the block adjacent to the target block to the capacitor, and the unit battery. Operating means for operating the connecting means to charge the capacitor, voltage detecting means for detecting a voltage of a unit cell connected to the capacitor based on a charging voltage of the capacitor, and detected by the voltage detecting means Reduction means for performing a process of reducing the variation in voltage between the unit cells based on the voltage,
The operating means provided in the at least one part of the state monitoring means is configured such that when connecting some of the unit cells to the capacitor, the charging polarity is not reversed and the unit cells in the target block are connected to the capacitor. The battery pack capacity adjustment device is characterized in that the connection means is operated so that the charging polarity is reversed. The state monitoring means further includes a reset means for discharging the charge of the capacitor,
The reset means provided in the at least one part of the state monitoring means discharges the charge of the capacitor when the unit battery in the target block is connected to the capacitor, and the some unit batteries are The capacity adjustment device for an assembled battery according to any one of claims 1 to 3, wherein the capacitor is not discharged when connected to the capacitor. About the assembled battery as a series connection body of battery cells, in the capacity adjustment device of the assembled battery for reducing the variation in the capacity of the unit battery that is one or a plurality of adjacent battery cells constituting the assembled battery,
Unit batteries constituting the assembled battery are grouped into a plurality of unit batteries adjacent to each other to form a block,
A state monitoring unit corresponding to each of the plurality of blocks;
At least a part of the state monitoring means includes a capacitor, a unit battery in the target block and a connection means for selectively connecting a part of the unit cells in the block adjacent to the target block to the capacitor, and the unit battery. Operating means for operating the connecting means to charge the capacitor, voltage detecting means for detecting a voltage of a unit cell connected to the capacitor based on a charging voltage of the capacitor, and detected by the voltage detecting means Reduction means for performing a process of reducing the variation in voltage between the unit cells based on the voltage,
The state monitoring means further includes a reset means for discharging the charge of the capacitor,
The reset means provided in the at least one part of the state monitoring means discharges the charge of the capacitor when the unit battery in the target block is connected to the capacitor, and the some unit batteries are The battery pack capacity adjustment device is characterized in that the capacitor is not discharged when connected to the capacitor. In the state monitoring unit, the connection unit selectively connects a part of unit cells in only one of the high potential side and the low potential side adjacent to the target block to the capacitor, and the reducing means, for a battery pack according to any one of claims 1 to 7, characterized in that include those having a function of discharging said portion of the unit cell which can be connected by said connecting means Capacity adjustment device. About the assembled battery as a series connection body of battery cells, in the capacity adjustment device of the assembled battery for reducing the variation in the capacity of the unit battery that is one or a plurality of adjacent battery cells constituting the assembled battery,
Unit batteries constituting the assembled battery are grouped into a plurality of unit batteries adjacent to each other to form a block,
A state monitoring unit corresponding to each of the plurality of blocks;
At least a part of the state monitoring means includes a capacitor, a unit battery in the target block and a connection means for selectively connecting a part of the unit cells in the block adjacent to the target block to the capacitor, and the unit battery. Operating means for operating the connecting means to charge the capacitor, voltage detecting means for detecting a voltage of a unit cell connected to the capacitor based on a charging voltage of the capacitor, and detected by the voltage detecting means Reduction means for performing a process of reducing the variation in voltage between the unit cells based on the voltage,
In the state monitoring unit, the connection unit selectively connects a part of unit cells in only one of the high potential side and the low potential side adjacent to the target block to the capacitor, and The battery pack capacity adjustment apparatus according to claim 1, wherein the reduction means includes a function of discharging the part of unit batteries connectable by the connection means. Of the state monitoring means, except for one of the highest potential side and the lowest potential side, the connection means is either the high potential side or the low potential side adjacent to the target block. A part of unit cells in the only block are selectively connected to the capacitor, and the reducing means has a function of discharging the part of unit cells connectable by the connecting means. The capacity adjustment apparatus for an assembled battery according to any one of claims 1 to 9 . About the assembled battery as a series connection body of battery cells, in the capacity adjustment device of the assembled battery for reducing the variation in the capacity of the unit battery that is one or a plurality of adjacent battery cells constituting the assembled battery,
Unit batteries constituting the assembled battery are grouped into a plurality of unit batteries adjacent to each other to form a block,
A state monitoring unit corresponding to each of the plurality of blocks;
At least a part of the state monitoring means includes a capacitor, a unit battery in the target block and a connection means for selectively connecting a part of the unit cells in the block adjacent to the target block to the capacitor, and the unit battery. Operating means for operating the connecting means to charge the capacitor, voltage detecting means for detecting a voltage of a unit cell connected to the capacitor based on a charging voltage of the capacitor, and detected by the voltage detecting means Reduction means for performing a process of reducing the variation in voltage between the unit cells based on the voltage,
Of the state monitoring means, except for one of the highest potential side and the lowest potential side, the connection means is either the high potential side or the low potential side adjacent to the target block. A part of unit cells in the only block are selectively connected to the capacitor, and the reducing means has a function of discharging the part of unit cells connectable by the connecting means. The capacity adjustment device of the assembled battery.

Images