JP2012161182A - Battery monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress variation in current consumption consumed in respective blocks when outputting output signals from respective monitoring ICs, in a configuration of detecting voltages of respective battery cells grouped for the respective blocks in the monitoring ICs.SOLUTION: Each monitoring IC 40 includes a drive circuit 41 for inputting output signals from another monitoring IC 40 of monitoring ICs 40, and as soon as the other monitoring IC 40 drives switching means 22 corresponding to the other monitoring IC 40 according to the output signals, driving the corresponding switching means 22 according to the output signals. Thus, the switching means 22 corresponding to the respective monitoring ICs 40 are simultaneously driven respectively by the drive circuits 41 of the respective monitoring ICs 40 according to the output signals outputted by one of the monitoring ICs 40. Thus, current amounts flowing to respective blocks 12 become the same, and the variation in the current consumption of the blocks 12 is suppressed.

Description

  The present invention relates to a battery monitoring device provided with a plurality of monitoring ICs that detect cell voltages of a plurality of battery cells constituting a block and output the detection results as output signals.

  Conventionally, the secondary battery control apparatus for vehicles is proposed by patent document 1, for example. In Patent Document 1, a configuration is proposed in which four battery cells, which are secondary batteries, are connected in series, and the terminals of each battery cell are connected to an ECU, which is an electronic control device. The ECU monitors each battery cell and performs charge / discharge control of each battery cell so that the state of charge (SOC) of each battery cell is, for example, 60%.

  On the other hand, for an assembled battery in which the number of battery cells is several tens or hundreds, a configuration in which monitoring is performed for each of a plurality of blocks in which a plurality of battery cells are grouped is common. This will be described with reference to FIG.

  As shown in FIG. 6, the assembled battery 10 is configured by connecting a plurality of battery cells 11 as a minimum unit in series, and a plurality of blocks 12 grouped for each predetermined number of battery cells 11 are connected in series. It has a configuration. A rechargeable lithium ion secondary battery is used as the battery cell 11. The assembled battery 10 is mounted on an electric vehicle such as a hybrid vehicle to serve as a drive source, and is used as a power source for driving a load such as a motor generator, a power source for an electronic device, and the like.

  A battery monitoring device is connected to such an assembled battery 10. The battery monitoring device includes a plurality of monitoring ICs 80 provided for each block 12. Each monitoring IC 80 is configured to monitor whether the block voltage of the block 12 to be monitored is normal. 6 shows a configuration in which the monitoring ICs 80 are provided for the three blocks 12, respectively.

  Further, an equalizing unit 20 is provided for each block 12 in order to equalize the block voltage of each block 12. The equalization unit 20 is configured by connecting a resistor 21 and a transistor 22 in series between the positive electrode side of the battery cell 11 on the highest voltage side of the block 12 and the negative electrode side of the battery cell 11 on the lowest voltage side. ing. Each equalization unit 20 is provided for each of the plurality of blocks 12. The resistor 21 is connected to the positive side of the block 12, and the transistor 22 is connected to the negative side of the block 12. For example, an NPN transistor is used as the transistor 22.

  The transistor 22 of the equalization unit 20 is driven by the corresponding monitoring IC 80. That is, each monitoring IC 80 is connected to the gate of each transistor 22. For example, when a high level signal is input to the gate of the transistor 22, a loop circuit (current consumption circuit) composed of the block 12 and the equalizing unit 20 is formed, and a current flows through the current consumption circuit to block the current. The voltage is controlled.

  The transistor 22 is driven by a monitoring IC 80 corresponding to the equalization unit 20 including the transistor 22. When the transistor 22 is driven, a current consumption circuit is formed between the equalization unit 20 and the block 12, in which a current flows through the loop path of the block 12, the resistor 21, the transistor 22, and the block 12.

  Here, the current consumption circuit on the lowest voltage side among the plurality of current consumption circuits constituted by the plurality of transistors 22 is a communication for outputting a signal from each monitoring IC 80 to the microcomputer 90 (hereinafter referred to as the microcomputer 90). Functions as a circuit. For this reason, the insulating element 30 is connected between the resistor 21 and the transistor 22 of the equalizing unit 20 constituting the current consumption circuit. Therefore, in the current consumption circuit on the lowest voltage side, a current flows through a loop path including the block 12, the resistor 21, the insulating element 30, the transistor 22, and the block 12. For example, a photocoupler is employed as the insulating element 30.

  As described above, the reason why the insulating element 30 is used between the equalizing unit 20 and the microcomputer 90 is that the voltage handled on each monitoring IC 80 side is higher than the voltage handled on the microcomputer 90 side, and thus the microcomputer 90 side. The high voltage system on the monitoring IC 80 side and the low voltage system on the microcomputer 90 side are insulated from each other by the insulating element 30. The reason why the signal is output to the microcomputer 90 from the current consumption circuit on the lowest voltage side is that the voltage of the entire assembled battery 10 is very high. This is because when the insulating element 30 is provided in the portion 20, the high withstand voltage insulating element 30 is required.

  In the equalizing unit 20 on the lowest voltage side, the insulating element 30 is not between the resistor 21 and the transistor 22, for example, between the high voltage side of the block 12 and the resistor 21, or between the transistor 22 and the block 12. It may be connected between the low voltage side.

  The microcomputer 90 performs equalization control of the block voltage of each block 12 based on the output signal of each monitoring IC 80 sent via the insulating element 30. A signal from the microcomputer 90 to the monitoring IC 80 is input to the monitoring IC 80 on the highest voltage side, for example, via an insulating element (not shown).

  In order to output the monitoring results of the monitoring ICs 80 from the equalization unit 20 corresponding to the block 12 on the lowest voltage side to the microcomputer 90, the monitoring ICs 80 are connected in series by a daisy chain method. Thereby, each monitoring IC 80 transfers the monitoring result that the block voltage is normal or abnormal to the monitoring IC 80 on the lowest voltage side via the daisy chain as an output signal of a certain duty ratio indicating normal or abnormal. In this case, each monitoring IC 80 outputs an output signal with a duty ratio indicating normal when the block voltage is normal, and outputs an output signal with the duty ratio changed when the block voltage is abnormal.

  Next, in the battery monitoring apparatus described above, the operation of outputting the monitoring result of each monitoring IC 80 to the microcomputer 90 will be described with reference to FIG. Here, the monitoring IC 80 corresponding to the block 12 on the highest voltage side is referred to as the first monitoring IC 80, and the second monitoring IC 80 and the third monitoring IC 80 are sequentially set to the low voltage side. That is, the monitoring IC 80 corresponding to the block 12 on the lowest voltage side is the third monitoring IC 80.

  First, the monitoring result of the first monitoring IC 80 is transferred to the second monitoring IC 80 and the third monitoring IC 80 by a daisy chain. In the section T30 shown in FIG. 7A, the transistor 22 of each equalization unit 20 is driven by each monitoring IC 80 in accordance with the output signal of the first monitoring IC 80. As a result, a current corresponding to the output signal of the first monitoring IC 80 flows through the current consumption circuit on the lowest voltage side, so that the output signal of the first monitoring IC 80 is isolated from the equalization unit 20 of the third monitoring IC 80. It is output to the microcomputer 90 via the element 30.

  Subsequently, the monitoring result of the second monitoring IC 80 is transferred to the third monitoring IC 80 and the first monitoring IC 80 by a daisy chain. In the section T31 shown in FIG. 7B, the transistor 22 of each equalization unit 20 is driven by each monitoring IC 80 according to the output signal of the second monitoring IC 80. As a result, a current corresponding to the output signal of the second monitoring IC 80 flows through the current consumption circuit on the lowest voltage side, so that the output signal of the second monitoring IC 80 is isolated from the equalization unit 20 of the third monitoring IC 80. It is output to the microcomputer 90 via the element 30.

  Thereafter, the monitoring result of the third monitoring IC 80 is transferred to the first monitoring IC 80 and the second monitoring IC 80 by a daisy chain. Therefore, in the section T32 shown in FIG. 7C, the transistor 22 of each equalization unit 20 is driven by each monitoring IC 80 according to the output signal of the third monitoring IC 80. As a result, a current flows through the equalization unit 20 corresponding to the third monitoring IC 80, so that the output signal of the third monitoring IC 80 is sent from the equalization unit 20 of the third monitoring IC 80 to the microcomputer 90 via the insulating element 30. Is output.

  As described above, in the communication between each monitoring IC 80 and the microcomputer 90, not only the transistor 22 of the equalization unit 20 corresponding to the block 12 on the lowest voltage side but also each equalization corresponding to the other block 12. The transistor 22 of the unit 20 is also driven according to the same output signal. For this reason, every time an output signal is output to the microcomputer 90, the amount of current flowing through each current consumption circuit, that is, each block 12, is the same, and the current consumed by each block 12 is the same. Thus, the transistor 22 can be driven by the output signal of the other monitoring IC 80 because the output signal is a signal having a certain duty ratio indicating normality or abnormality.

  Therefore, even when the output signal is output from the lowest voltage side current consumption circuit to the microcomputer 90, when the output signal of each monitoring IC 80 is output to the microcomputer 90, the variation in the current consumption of each block 12 varies. It does not occur.

Japanese Patent Laid-Open No. 2002-354692

  In the above conventional technique, the battery monitoring device is configured to detect the block voltage of the block 12, but the control for reducing the variation in each cell voltage by detecting the individual cell voltage of each battery cell 11. It is desired to do.

  Therefore, instead of the monitoring IC 80 used in FIG. 6, the cell voltage for each battery cell 11 is detected and AD converted, and the AD conversion is performed on the duty ratio of the output signal according to the magnitude of the cell voltage. It is conceivable to employ a monitoring IC that changes the output. That is, each monitoring IC 80 in the battery monitoring device shown in FIG. 6 is replaced with the above-described new monitoring IC. Even if a new type of monitoring IC is adopted, the configuration in which the current consumption circuit on the lowest voltage side is a communication circuit with the microcomputer 90 is the same as the conventional one.

  However, the new monitoring IC drives the transistor 22 corresponding to the monitoring IC, but only transfers the output signal input from another monitoring IC via the daisy chain except the monitoring IC on the lowest voltage side. The transistor 22 is not configured to be driven by an output signal input from another monitoring IC. For this reason, there is a problem that the current consumed in each block 12 varies. This will be described with reference to FIG. As for the new type of monitoring IC, the monitoring IC corresponding to the block 12 on the highest voltage side is the first monitoring IC, and the second monitoring IC and the third monitoring IC are sequentially arranged on the low voltage side.

  In a section T40 shown in FIG. 8, the transistor 22 corresponding to the third monitoring IC is driven according to the output signal of the first monitoring IC shown in FIG. At 90, the output signal of the first monitoring IC is output. In this case, the transistor 22 corresponding to the second monitoring IC is not driven, and no current is consumed in the block 12 corresponding to the second monitoring IC.

  Similarly, in the section T41 shown in FIG. 8, the transistor 22 corresponding to the third monitoring IC is driven according to the output signal of the second monitoring IC shown in FIG. Then, the output signal of the second monitoring IC is output to the microcomputer 90. In this case, the transistor 22 corresponding to the first monitoring IC is not driven, and no current is consumed in the block 12 corresponding to the first monitoring IC.

  In a section T42 shown in FIG. 8, the transistor 22 corresponding to the third monitoring IC is driven according to the output signal of the third monitoring IC shown in FIG. Then, the output signal of the third monitoring IC is output to the microcomputer 90. In this case, each transistor 22 corresponding to the first monitoring IC and the second monitoring IC is not driven, and current is consumed only by the block 12 corresponding to the third monitoring IC.

  As described above, in the block 12 corresponding to the first monitoring IC, current is consumed when the output signal is output from the first monitoring IC, and in the block 12 corresponding to the second monitoring IC, the second monitoring IC. Current is consumed when an output signal is output from. On the other hand, in the block 12 corresponding to the third monitoring IC in which communication with the microcomputer 90 is performed, from the first monitoring IC and the second monitoring IC in addition to when the output signal of the third monitoring IC is output. Since current is also consumed when an output signal is output, current is always consumed. Therefore, the current consumed in each block 12 varies.

  In the above description, the current consumption circuit on the lowest voltage side is the communication circuit with the microcomputer 90. Of course, the current consumption circuit on the high voltage side may be the communication circuit with the microcomputer 90.

  In view of the above-described points, the present invention consumes each block when outputting an output signal from each monitoring IC in a battery monitoring device that detects the voltage of each battery cell grouped for each block by the monitoring IC. It aims at suppressing the variation in consumption current.

  In order to achieve the above object, the invention according to claim 1 is provided corresponding to each of a plurality of blocks in which a plurality of battery cells are grouped for each predetermined number of battery cells. A plurality of monitoring ICs for detecting the voltages of the battery cells constituting the block and outputting the detection results as output signals, and provided for each of the plurality of blocks, and between the positive electrode side and the negative electrode side of the block Connected and driven according to the output signal of the corresponding monitoring IC, it is provided with a plurality of switching means constituting a current consumption circuit in which a current flows between the block.

  The plurality of monitoring ICs are connected in a daisy chain manner so that an output signal output from any one of the plurality of monitoring ICs is transferred to all the monitoring ICs. Any one of the plurality of configured current consumption circuits is configured to function as a communication circuit that outputs the output signals of the plurality of monitoring ICs to the monitoring unit.

  Each of the plurality of monitoring ICs inputs an output signal from another monitoring IC among the plurality of monitoring ICs by a daisy chain method, and the other monitoring ICs daisy-chain switching means corresponding to the other monitoring ICs. It is characterized by comprising driving means for driving the corresponding switching means according to the output signal at the same time as driving according to the output signal by the chain system.

  According to this, each switching means corresponding to each monitoring IC is simultaneously driven by the driving means of each monitoring IC according to the output signal output by any monitoring IC, so that the amount of current flowing through each current consumption circuit is respectively Be the same. Therefore, since the consumption current consumed in each block is the same, variation in consumption current consumed in each block can be suppressed.

  In the invention according to claim 2, the battery pack constituting the block is provided corresponding to each of a plurality of blocks in which assembled batteries in which a plurality of battery cells are connected in series are grouped for each predetermined number of battery cells. A plurality of monitoring ICs for detecting cell voltages and outputting the detection results as output signals, and provided for each of the plurality of blocks, and connected between the positive and negative sides of the block, And a plurality of switching means constituting a current consumption circuit through which a current flows, so that an output signal output from any one of the plurality of monitoring ICs is transferred to all the monitoring ICs A plurality of monitoring ICs are connected in a daisy chain manner.

  Further, the switching means corresponding to any one of the plurality of monitoring ICs is driven in accordance with the output signal of the monitoring IC or the output signal input to the monitoring IC from the other monitoring ICs by the daisy chain method. In addition, the current consumption circuit configured by the switching unit corresponding to the monitoring IC is configured as a communication circuit that outputs the output signals of the plurality of monitoring ICs to the monitoring unit.

  The wiring branching from the communication circuit is provided with driving means for driving the switching means corresponding to the other monitoring ICs simultaneously with the switching means corresponding to the monitoring IC being driven according to the output signal. Features.

  According to this, when the switching means of the monitoring IC is driven according to the output signal, the switching means other than the monitoring IC are simultaneously driven by the driving means, so that the amount of current flowing through each consumption current circuit is the same. . Therefore, since the consumption current consumed in each block is the same, variation in consumption current consumed in each block can be suppressed.

  In the invention according to claim 3, the battery pack constituting the block is provided corresponding to each of a plurality of blocks in which assembled batteries in which a plurality of battery cells are connected in series are grouped for each predetermined number of battery cells. A plurality of monitoring ICs are provided for detecting cell voltages and outputting the detection results as output signals.

  In addition, it is provided for each of the plurality of blocks, and is connected between the positive side and the negative side of the block, and is driven according to the output signal of the corresponding monitoring IC so that current flows between the blocks. A plurality of first switching means constituting one current consumption circuit are provided.

  The plurality of monitoring ICs are connected in a daisy chain manner so that an output signal output from any one of the plurality of monitoring ICs is transferred to all the monitoring ICs, and the plurality of first switching Any one of the plurality of first consumption current circuits configured by the means is configured as a communication circuit that outputs the output signals of the plurality of monitoring ICs to the monitoring means.

  Further, the block is provided for each of the plurality of monitoring ICs, connected between the positive side and the negative side of the block, and driven according to the inverted signal obtained by inverting the output signal of the corresponding monitoring IC. A plurality of second switching means each constituting a second current consumption circuit in which a current flows between the first current consumption circuit, the duty ratio of the output signal indicating the timing of driving the first switching means in the first current consumption circuit, and the second consumption The sum of both the duty ratio of the inverted signal indicating the timing for driving the second switching means in the current circuit is 100%.

  According to this, for each block, a two-path consumption current circuit of the first consumption current circuit according to the first switching means and the second consumption current circuit according to the second switching means is formed. When current flows in one side, current does not flow in the other, and when current does not flow in one of the current consumption circuits, it flows in the other, so that current always flows in each block regardless of the duty ratio of the output signal. can do. Therefore, variations in current consumption consumed in each block can be suppressed.

1 is an overall configuration diagram of a battery monitoring system including a battery monitoring device according to a first embodiment of the present invention. It is a timing chart for demonstrating the action | operation of the battery monitoring apparatus shown by FIG. It is a whole block diagram of the battery monitoring system containing the battery monitoring apparatus which concerns on 2nd Embodiment of this invention. It is a whole block diagram of the battery monitoring system containing the battery monitoring apparatus which concerns on 3rd Embodiment of this invention. It is a timing chart for demonstrating the action | operation of the battery monitoring apparatus shown by FIG. It is a block diagram of the conventional battery monitoring apparatus. It is a timing chart for demonstrating the action | operation of the battery monitoring apparatus shown by FIG. It is a timing chart which shows the output signal for driving the transistor which each monitoring IC uses when a monitoring IC is made into a cell voltage detection system.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In the following, the same components as those shown in FIG. Further, the description of the same components as those in FIG. 6 is omitted.

  FIG. 1 is an overall configuration diagram of a battery monitoring system including a battery monitoring apparatus according to the present embodiment. As shown in this figure, the battery monitoring system includes an assembled battery 10 and a battery monitoring device.

  The battery monitoring device is a device that monitors individual battery cells 11 of the battery pack 10, and includes a plurality of equalization units 20, insulating elements 30, a plurality of monitoring ICs 40, and a microcomputer 50. Yes. The equalizing section 20 and the insulating element 30 are the same as those shown in FIG.

  The microcomputer 50 is a control circuit that includes a CPU, ROM, EEPROM, RAM, and the like (not shown) and operates according to a program stored in the ROM. Such a microcomputer 50 outputs a command signal to the monitoring IC 40 to cause the monitoring IC 40 to execute processing such as detection and equalization of the cell voltage of each battery cell 11. Further, the microcomputer 50 acquires the output signal of each monitoring IC 40 from the current consumption circuit (communication circuit) on the lowest voltage side via the insulating element 30, and controls each monitoring IC 40 based on the output signal.

  Each of the plurality of monitoring ICs 40 is an IC configured to detect the cell voltage of the battery cell 11. Each monitoring IC 40 is operated by being connected between both electrodes of the corresponding block 12 and being supplied with power, and both end electrodes of the battery cells 11 constituting the corresponding block 12 are respectively connected. Although not shown, the circuit for detecting the cell voltage includes, for example, a voltage dividing circuit constituted by a resistor, a selection circuit constituted by a switch, a comparison circuit constituted by a comparator, an AD conversion circuit for AD converting the cell voltage, etc. It is constituted by a circuit.

  Each monitoring IC 40 outputs an AD-converted cell voltage signal as an output signal having a duty ratio corresponding to the voltage value of the cell voltage. For example, the duty ratio of the output signal indicating the cell voltage increases as the voltage value of the cell voltage increases.

  Each monitoring IC 40 is connected in a daisy chain manner so that an output signal output from any one of the monitoring ICs 40 is transferred to all the monitoring ICs 40. Accordingly, each monitoring IC 40 detects the cell voltage of the battery cell 11 and outputs the detection result to another monitoring IC 40 as an output signal. The signal transfer is performed so that signals are sequentially output from the monitoring IC 40 corresponding to the high-voltage block 12 to the monitoring IC 40 corresponding to the low-voltage block 12, for example.

  Further, each monitoring IC 40 includes a driving circuit 41 for driving the transistor 22. When the drive circuit 41 receives an output signal from another monitoring IC 40 among the plurality of monitoring ICs 40 by a daisy chain method, the other monitoring IC 40 drives the transistor 22 corresponding to the other monitoring IC 40 according to the output signal. At the same time, the corresponding transistor 22 is driven in accordance with the output signal. This will be described with reference to FIG.

  Note that the monitoring IC 40 corresponding to the block 12 on the highest voltage side is the first monitoring IC 40, and the second monitoring IC 40 and the third monitoring IC 40 are in turn on the low voltage side.

  First, when the output signal of the first monitoring IC 40 is output to the microcomputer 50, the output signal of the first monitoring IC 40 is transferred to the second monitoring IC 40 and the third monitoring IC 40 by a daisy chain. Therefore, in the section T10 shown in FIG. 2, the transistors 22 of the equalization units 20 are simultaneously driven by the drive circuit 41 of each monitoring IC 40 according to the output signal of the first monitoring IC 40 shown in FIG. . That is, in the section T10, all signals for driving the transistors 22 are output signals of the first monitoring IC 40. As a result, the amount of current flowing through each current consumption circuit, that is, each block 12, becomes the amount of current according to the output signal of the first monitoring IC 40, and the current consumed by each block 12 is the same.

  In addition, since the current due to the driving of the transistor 22 according to the output signal of the first monitoring IC 40 flows in the current consumption circuit on the lowest voltage side, the output signal of the first monitoring IC 40 is consumed on the lowest voltage side. Data is output from the current circuit to the microcomputer 50 via the insulating element 30.

  Similarly, the output signal of the second monitoring IC 40 is transferred to the third monitoring IC 40 and the first monitoring IC 40 by a daisy chain. Therefore, in the section T11 shown in FIG. 2, the transistors 22 of the equalization units 20 are simultaneously driven by the drive circuit 41 of each monitoring IC 40 according to the output signal of the second monitoring IC 40 shown in FIG. . That is, in the section T11, all signals for driving the transistors 22 are output signals of the second monitoring IC 40. As a result, the amount of current flowing through each current consumption circuit, that is, each block 12, becomes the amount of current according to the output signal of the second monitoring IC 40, and the current consumed by each block 12 is the same.

  In addition, since the current due to the transistor 22 being driven flows according to the output signal of the second monitoring IC 40 in the current consumption circuit on the lowest voltage side, the output signal of the second monitoring IC 40 is consumed on the lowest voltage side. Data is output from the current circuit to the microcomputer 50 via the insulating element 30.

  Further, the output signal of the third monitoring IC 40 is transferred to the first monitoring IC 40 and the second monitoring IC 40 by a daisy chain. Therefore, in the section T12 shown in FIG. 2, the transistors 22 of the equalization units 20 are simultaneously driven by the drive circuit 41 of each monitoring IC 40 according to the output signal of the third monitoring IC 40 shown in FIG. . That is, in the section T12, all signals for driving the transistors 22 are output signals of the third monitoring IC 40. As a result, the amount of current flowing through each current consumption circuit, that is, each block 12, becomes the amount of current according to the output signal of the third monitoring IC 40, and the current consumed by each block 12 is the same.

  In addition, since the current due to the transistor 22 being driven in accordance with the output signal of the third monitoring IC 40 flows in the current consumption circuit on the lowest voltage side, the output signal of the third monitoring IC 40 is consumed on the lowest voltage side. Data is output from the current circuit to the microcomputer 50 via the insulating element 30.

  As described above, each transistor 22 corresponding to each monitoring IC 40 is simultaneously driven by the drive circuit 41 of each monitoring IC 40 in accordance with the output signal output by any monitoring IC 40, so that the output signal of which monitoring IC 40 is sent to the microcomputer. Also when transferring to 50, the amount of current flowing through each consumption current circuit is the same. Therefore, variation in consumption current consumed in each block 12 can be suppressed.

  Regarding the correspondence between the description of the present embodiment and the description of the claims, the microcomputer 50 corresponds to the “monitoring means” in the claims, and the drive circuit 41 corresponds to the “driving means” in the claims. Corresponding to The transistor 22 corresponds to “switching means” in the claims.

(Second Embodiment)
In the present embodiment, parts different from the first embodiment will be described. In the first embodiment, each monitoring IC 40 drives the corresponding transistor 22, but in this embodiment, another current consumption circuit is configured based on the current flowing in the current consumption circuit on the lowest voltage side. It is characterized in that the transistor 22 is driven.

  FIG. 3 is an overall configuration diagram of a battery monitoring system including the battery monitoring apparatus according to the present embodiment. As shown in this figure, in the battery monitoring apparatus according to this embodiment, the transistor 22 constituting the current consumption circuit on the lowest voltage side is driven by the monitoring IC 40 on the lowest voltage side. The gate of the transistor 22 constituting the current consumption circuit on the higher voltage side than the current consumption circuit on the lowest voltage side is not connected to the monitoring IC 40.

  Note that the monitoring IC 40 on the lowest voltage side may drive the corresponding transistor 22 by the drive circuit 41 shown in the first embodiment. In the present embodiment, the drive circuit 41 drives the transistor 22 in accordance with an output signal input from the monitoring IC 40 other than the monitoring IC 40 on the lowest voltage side to the monitoring IC 40 on the lowest voltage side or an output signal of its own monitoring IC 40. Is configured to do.

  In the battery monitoring apparatus configured as described above, the battery monitoring apparatus further includes a drive unit 60. The drive unit 60 operates when current flows through the current consumption circuit on the lowest voltage side, and causes the same amount of current to flow through the current consumption circuit on the higher voltage side than the current consumption circuit on the lowest voltage side. It is configured.

  Specifically, the driving unit 60 is branched from the wiring 23 connected to the transistor 22 corresponding to the monitoring IC 40 on the lowest voltage side, and includes a protective resistor 61 and two PNP type transistors 62. I have. One end of the resistor 61 is connected to the wiring 23, and the other end is connected to the gate of each transistor 62. Each transistor 62 is provided for each equalization unit 20. The emitter of each transistor 62 is connected to the positive side of each block 12, and the collector is connected to the gate of each transistor 22.

  As a result, when a current flows through the current consumption circuit on the lowest voltage side, the gate voltage of each transistor 62 decreases, so that each transistor 62 is turned on. As a result, the transistors 22 constituting the current consumption circuit on the higher voltage side than the current consumption circuit on the lowest voltage side are turned on. That is, simultaneously with the timing at which the transistor 22 corresponding to the monitoring IC 40 on the lowest voltage side is driven according to the output signal, the transistors 22 corresponding to the other monitoring ICs 40 are respectively driven by the drive unit 60.

  Therefore, in the section T10 shown in FIG. 2, when the transistor 22 constituting the current consumption circuit (communication circuit) on the lowest voltage side is driven according to the output signal of the first monitoring IC 40 shown in FIG. The transistors 22 constituting other current consumption circuits are also simultaneously driven by the drive unit 60 according to the output signal of the first monitoring IC 40.

  Similarly, in the section T11 shown in FIG. 2, the transistor 22 constituting the current consumption circuit (communication circuit) on the lowest voltage side is driven according to the output signal of the second monitoring IC 40 shown in FIG. The transistors 22 constituting other current consumption circuits are also simultaneously driven by the drive unit 60 according to the output signal of the second monitoring IC 40. In the section T12 shown in FIG. 2, when the transistor 22 constituting the current consumption circuit (communication circuit) on the lowest voltage side is driven according to the output signal of the third monitoring IC 40 shown in FIG. The transistors 22 constituting other current consumption circuits are also simultaneously driven by the driving unit 60 in accordance with the output signal of the third monitoring IC 40.

  As described above, when the transistor 22 corresponding to the monitoring IC 40 on the lowest voltage side is driven according to the output signal of each monitoring IC 40, the transistor corresponding to the monitoring IC 40 other than the monitoring IC 40 on the lowest voltage side by the driving unit 60. 22 is also driven simultaneously. For this reason, the amount of current flowing through each current consumption circuit is the same, and the current consumption consumed by each block 12 is the same. Therefore, variation in consumption current consumed in each block 12 can be suppressed.

  For the correspondence between the description of the present embodiment and the description of the claims, the drive unit 60 corresponds to the “drive means” of the claims. The transistor 22 corresponds to “switching means” in the claims.

(Third embodiment)
In the present embodiment, parts different from the first embodiment will be described. In the first embodiment, the transistors 22 are simultaneously driven by the drive circuits 41 provided in the respective monitoring ICs 40. However, in this embodiment, each current consumption circuit provided for each block 12 has two systems, and each block 12 The duty ratio of the current flowing in the block 12 is set to 100%, so that the variation in the current consumption of each block 12 is suppressed.

  FIG. 4 is an overall configuration diagram of a battery monitoring system including the battery monitoring apparatus according to the present embodiment. In the present embodiment, the equalization unit 20, the transistor 22, and the resistor 21 in the battery monitoring device illustrated in FIG. 1 are referred to as a first equalization unit 20, a first transistor 22, and a first resistor 21. Each monitoring IC 40 includes a driving circuit (not shown) for driving the corresponding first transistor 22. In addition, when the first transistor 22 is driven, a current consumption circuit in which a current flows through a loop path including the block 12, the first resistor 21, the first transistor 22, and the block 12 is referred to as a first current consumption circuit.

  Further, in the present embodiment, a second equalization unit 70 that performs an inversion operation with respect to the first equalization unit 20 is provided for each block 12. Specifically, for each block 12, the second equalization unit 70 is connected between the positive electrode side of the battery cell 11 on the highest voltage side of the block 12 and the negative electrode side of the battery cell 11 on the lowest voltage side. A resistor 71 and a second transistor 72 are connected in series, and an inverter 73 is connected between the gate of the first transistor 22 and the gate of the second transistor 72.

  In such a configuration, the second transistor 72 is driven in accordance with the inverted signal obtained by inverting the output signal for driving the first transistor 22 by the inverter 73, so that the block 12, the second resistor A loop path (second current consumption circuit) 71, the second transistor 72, and the block 12 is formed.

  Therefore, when the first transistor 22 is driven, a current flows through the first current consumption circuit, but no current flows through the second current consumption circuit. On the other hand, when the second transistor 72 is driven, a current flows through the second current consumption circuit, but no current flows through the first current consumption circuit. That is, the sum of both the duty ratio of the output signal indicating the timing of driving the first transistor 22 in the first current consumption circuit and the duty ratio indicating the timing of driving the second transistor 72 in the second current consumption circuit is 100%. This will be described with reference to FIG.

  First, when the output signal of the first monitoring IC 40 is output to the microcomputer 50, the output signal of the first monitoring IC 40 is transferred to the second monitoring IC 40 and the third monitoring IC 40 by a daisy chain. In the section T20 shown in FIG. 5, the first transistor 22 corresponding to the first monitoring IC 40 and the first transistor 22 corresponding to the third monitoring IC 40 on the lowest voltage side that communicates with the microcomputer 50 are shown in FIG. Driven according to the output signal of the first monitoring IC 40 shown in FIG. Further, the second transistor 72 corresponding to the first monitoring IC 40 and the second transistor 72 corresponding to the third monitoring IC 40 are driven according to the inverted signal of the output signal of the first monitoring IC 40 shown in FIG. The Therefore, a current having a duty ratio of 100% flows through the block 12 corresponding to the first monitoring IC 40 and the block 12 corresponding to the third monitoring IC 40.

  On the other hand, the first transistor 22 corresponding to the second monitoring IC 40 is not driven, but the second transistor 72 is continuously driven during the section T20. Therefore, a current having a duty ratio of 100% flows through the block 12 corresponding to the second monitoring IC 40.

  Subsequently, when the output signal of the second monitoring IC 40 is output to the microcomputer 50, as in the case of the first monitoring IC 40, in the section T21 shown in FIG. 5, the first monitoring IC 40 corresponding to the second monitoring IC 40 is displayed. The first transistor 22 corresponding to the third monitoring IC 40 that communicates with the transistor 22 and the microcomputer 50 is driven according to the output signal of the second monitoring IC 40 shown in FIG. The second transistor 72 corresponding to the second monitoring IC 40 and the second transistor 72 corresponding to the third monitoring IC 40 are driven according to the inverted signal of the output signal of the second monitoring IC 40 shown in FIG. 5B. The Therefore, a current having a duty ratio of 100% flows through the block 12 corresponding to the second monitoring IC 40 and the block 12 corresponding to the third monitoring IC 40.

  The first transistor 22 corresponding to the first monitoring IC 40 is not driven, but the second transistor 72 is continuously driven during the section T21. Therefore, a current having a duty ratio of 100% flows through the block 12 corresponding to the first monitoring IC 40.

  Thereafter, when the output signal of the third monitoring IC 40 is output to the microcomputer 50, in the section T22 shown in FIG. 5, the first transistor 22 corresponding to the third monitoring IC 40 is shown in FIG. Driven according to the output signal of the third monitoring IC 40. The second transistor 72 corresponding to the third monitoring IC 40 is driven according to the inverted signal of the output signal of the second monitoring IC 40 shown in FIG. Therefore, a current having a duty ratio of 100% flows through the block 12 corresponding to the third monitoring IC 40.

  The first transistor 22 corresponding to the first monitoring IC 40 and the first transistor 22 corresponding to the second monitoring IC 40 are not driven, but the second transistor 72 is continuously driven during the section T22. . Therefore, a current having a duty ratio of 100% flows through the block 12 corresponding to the second monitoring IC 40 and the block 12 corresponding to the second monitoring IC 40.

  As described above, each block 12 is provided with a two-path current consumption circuit including the first current consumption circuit related to the first transistor 22 and the second current consumption circuit related to the second transistor 72. Every twelve, when a current flows through one of the current consumption circuits, a current flows through the other, and when no current flows through one of the current consumption circuits, the current flows through the other. For this reason, regardless of the duty ratio of the output signal of each monitoring IC 40, a current having a duty ratio of 100% can always flow through any block 12, thereby suppressing variations in current consumption consumed by each block 12. be able to.

  As for the correspondence between the description of the present embodiment and the description of the claims, the first transistor 22 corresponds to “first switching means” in the claims, and the second transistor 72 corresponds to the claims. To “second switching means”.

(Other embodiments)
Each configuration of the battery monitoring device shown in each of the above embodiments is an example, and the configuration is not limited to the configuration shown above, and other configurations including the features of the present invention may be employed. For example, from the viewpoint of withstand voltage, the current consumption circuit on the lowest voltage side is the communication circuit with the microcomputer 50, but the current consumption circuit on the higher voltage side may be the communication circuit with the microcomputer 50.

  In addition, the number of blocks 12 and the number of monitoring ICs 40 in each of the above embodiments are merely examples, and of course are not limited to these numbers. Similarly, the configurations of the equalization units 20 and 70 may be other configurations using the transistors 22 and 72.

  Furthermore, the configuration of the drive unit 60 shown in the second embodiment is also an example, and the drive unit 60 may be configured using an NPN type instead of the PNP type transistor 62. Further, the wiring 23 from which the driving unit 60 is branched may be any wiring that constitutes a communication circuit. The branching location is not limited to the wiring 23 connected to the transistor 22, for example, between the resistor 21 and the insulating element 30. A wiring or a wiring between the insulating element 30 and the transistor 22 may be used.

10 battery pack 11 battery cell 12 block 22 transistor, first transistor (switching means, first switching means)
23 Wiring 40 Monitoring IC
41 Drive circuit (drive means)
50 Microcomputer (monitoring means)
60 Drive part (drive means)
72 Second transistor (second switching means)

Claims (3)

A battery pack in which a plurality of battery cells are connected in series is provided corresponding to each of a plurality of blocks in which a predetermined number of battery cells are grouped, and the voltage of each battery cell constituting the block is detected and detected. A plurality of monitoring ICs that output the results as output signals;
Consumption that is provided for each of the plurality of blocks and that is connected between the positive side and the negative side of the block and that is driven according to the output signal of the corresponding monitoring IC so that current flows between the blocks. Comprising a plurality of switching means constituting a current circuit;
The plurality of monitoring ICs are connected in a daisy chain manner so that an output signal output from any one of the plurality of monitoring ICs is transferred to all the monitoring ICs.
Any one of the plurality of consumption current circuits configured by the plurality of switching means is configured to function as a communication circuit that outputs the output signals of the plurality of monitoring ICs to the monitoring means, respectively. A battery monitoring device,
When the plurality of monitoring ICs input output signals from other monitoring ICs among the plurality of monitoring ICs by the daisy chain method, the other monitoring ICs set switching means corresponding to the other monitoring ICs to the daisy chain. A battery monitoring device comprising driving means for driving a corresponding switching means according to the output signal simultaneously with driving according to the output signal by a chain system. A battery pack in which a plurality of battery cells are connected in series is provided corresponding to each of a plurality of blocks in which a predetermined number of battery cells are grouped, and the voltage of each battery cell constituting the block is detected and detected. A plurality of monitoring ICs that output the results as output signals;
Provided for each of the plurality of blocks, and connected between a positive side and a negative side of the block, comprising a plurality of switching means constituting a current consumption circuit in which a current flows between the blocks,
A battery monitoring device in which the plurality of monitoring ICs are connected in a daisy chain manner so that an output signal output from any one of the plurality of monitoring ICs is transferred to all the monitoring ICs.
Switching means corresponding to any one of the plurality of monitoring ICs is driven in accordance with an output signal of the monitoring IC or an output signal input to the monitoring IC from the other monitoring IC by the daisy chain method. In addition, the current consumption circuit configured by the switching unit corresponding to the monitoring IC is configured as a communication circuit that outputs the output signals of the plurality of monitoring ICs to the monitoring unit,
The wiring branched from the communication circuit is provided with driving means for driving the switching means corresponding to the other monitoring IC at the same time that the switching means corresponding to the monitoring IC is driven according to the output signal. A battery monitoring device. A battery pack in which a plurality of battery cells are connected in series is provided corresponding to each of a plurality of blocks in which a predetermined number of battery cells are grouped, and the voltage of each battery cell constituting the block is detected and detected. A plurality of monitoring ICs that output the results as output signals;
Provided for each of the plurality of blocks, connected between the positive side and the negative side of the block, and driven according to the output signal of the corresponding monitoring IC so that current flows between the blocks. A plurality of first switching means constituting one current consumption circuit;
The plurality of monitoring ICs are connected in a daisy chain manner so that an output signal output from any one of the plurality of monitoring ICs is transferred to all the monitoring ICs.
Any one of the plurality of first consumption current circuits configured by the plurality of first switching units is configured as a communication circuit that outputs the output signals of the plurality of monitoring ICs to the monitoring unit, respectively. Battery monitoring device,
Provided for each of the plurality of monitoring ICs and connected between the positive side and the negative side of the block, and driven according to an inverted signal obtained by inverting the output signal of the corresponding monitoring IC, A plurality of second switching means each constituting a second current consumption circuit through which current flows.
The duty ratio of the output signal indicating the timing for driving the first switching means in the first current consumption circuit, and the duty ratio of the inverted signal indicating the timing for driving the second switching means in the second current consumption circuit. And the sum of the two is 100%.

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