JP2012095388A - Battery state monitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery state monitor capable of detecting abnormality of a battery cell in a short time and capable of accurately performing detailed abnormality treatment.SOLUTION: The battery state monitor monitors the state of a battery cell 10 in a battery pack 1 consisting of the plurality of battery cells 10 connected in series. It includes a comparison circuit 3 which compares respective cell voltage and threshold values of the plurality of battery cells 10, a voltage detection circuit 5 which detects voltage information of each of the plurality of battery cells 10, a monitoring processing part (monitoring means) 61 which monitors the state of the battery cell 10 based on the comparison result outputted from the comparison circuit 3 and the voltage information outputted from the voltage detection circuit 5, and a communication processing part (output means) 62 which outputs the comparison result, with preference being given over the voltage information, to the monitoring processing part 61.

Description

  The present invention relates to a battery state monitoring device that monitors a charge / discharge state of an assembled battery.

  This type of battery status monitoring device includes a comparator that compares the magnitude relationship between the voltage across the battery cells and the threshold value of each battery cell of the assembled battery configured by connecting a plurality of battery cells in series. A configuration of a comparison method that detects a charge / discharge state of each battery cell according to a comparison result of each corresponding comparator is known (for example, Patent Document 1).

  The battery state monitoring device includes an AD converter that detects a voltage across each battery cell in the assembled battery and outputs a digital signal, and detects a charge / discharge state of the battery cell according to the output of the AD converter. The system configuration is also known.

Japanese Patent Laid-Open No. 10-21965

  By the way, although the battery status monitoring device of the comparison method can detect the abnormality of the battery cell in a short time, for example, the reference voltage is a constant voltage or the battery cell in which the abnormality is detected cannot be specified. There is a drawback that the generality of the abnormal processing at the time of detection is lacking.

  On the other hand, the voltage detection type battery state detection device can detect the voltage across the battery cell with higher accuracy than the comparison method, and therefore, when the abnormality of the battery cell is detected, a fine abnormality process (fail) is performed. Safe) can be executed accurately. However, since it is necessary to detect the voltage at both ends of each battery cell, there is a disadvantage that abnormality of the battery cell cannot be detected in a short time.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a battery state monitoring device capable of detecting abnormalities in battery cells in a short period of time and capable of accurately executing extremely detailed abnormality processing.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a battery state monitoring device for monitoring a state of a battery cell in an assembled battery configured by connecting a plurality of battery cells in series. Based on the comparison means for comparing the voltage and the threshold, the voltage detection means for detecting the voltage information of the plurality of battery cells, the comparison result output from the comparison means, and the voltage information output from the voltage detection means It is characterized by comprising monitoring means for monitoring the state of the cell and output means for giving priority to the comparison result over the voltage information and outputting it to the monitoring means.

  According to this, since each of the comparison means and the voltage detection means is provided, the abnormality of the battery cell can be detected in a short time based on the comparison result output from the comparison means. Furthermore, it is possible to accurately execute an extremely detailed abnormality process when detecting an abnormality of the battery cell based on the highly accurate voltage information output from the voltage detection means.

  In addition to these, since the comparison result output from the comparison means is output to the monitoring means with priority over the voltage information output from the voltage detection means, the battery cell abnormality is detected quickly, and each battery is detected. Appropriate protection of the cell and its peripheral devices can be achieved.

  The “voltages of the plurality of battery cells” and the “voltage information of the plurality of battery cells” include the voltage of one battery cell (cell voltage) in the plurality of battery cells and some of the battery cells in the plurality of battery cells. Voltage (block voltage).

  Specifically, as in the invention according to claim 2, in the battery state monitoring device according to claim 1, the output means includes an output timing of a comparison result output from the comparison means to the monitoring means, and a voltage detection means. When the output timing of the voltage information output from to the monitoring means overlaps, the comparison result can be prioritized and output to the monitoring means over the voltage information.

  According to a third aspect of the present invention, in the battery state monitoring device according to the first or second aspect, a battery cell that has been compared with a threshold value among a plurality of battery cells based on an output from the comparison means. Cell identifying means for outputting identification information unique to the identification to the monitoring means is provided.

  According to this, since the monitoring means can identify the battery cell that has been compared with the threshold value by the comparison means, it is possible to identify which of the plurality of battery cells is abnormal. Is possible.

  According to a fourth aspect of the present invention, in the battery state monitoring device according to any one of the first to third aspects, the comparing means is configured such that the voltage of the plurality of battery cells is equal to or higher than the threshold value or lower than the threshold value. In this case, an abnormality signal indicating an abnormality of the battery cell can be output as a comparison result.

  According to a fifth aspect of the present invention, in the battery state monitoring device according to any one of the first to fourth aspects, the output means is connected to the comparison means and the voltage detection means, respectively. Is characterized in that each of the comparison means and the voltage detection means (5) is connected via the output means.

  According to this, the comparison result output from the comparison means to the monitoring means and the voltage information output from the voltage detection means to the monitoring means can be output to the monitoring means via one output means. For this reason, the output line for outputting an output signal to the monitoring means can be shared by the comparison means and the voltage detection means.

It is a schematic block diagram of the battery monitoring system containing the battery state monitoring apparatus of 1st Embodiment. It is explanatory drawing explaining the action | operation of the battery condition monitoring apparatus of 1st Embodiment. It is a schematic block diagram of the battery monitoring system containing the battery state monitoring apparatus of 2nd Embodiment. It is explanatory drawing explaining the action | operation of the battery state monitoring apparatus of 2nd Embodiment.

  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 FIGS. 1 and 2. FIG. 1 is a schematic configuration diagram of a battery monitoring system including a battery state monitoring device 2 according to the present embodiment. As shown in FIG. 1, the battery monitoring system includes an assembled battery 1 and a battery state monitoring device 2 that monitors the charge / discharge state of the assembled battery 1.

  The assembled battery 1 is a battery group in which a plurality of battery cells 10 as a minimum unit are connected in series. The assembled battery 1 of the present embodiment is configured by, for example, twelve (V1 to V12) battery cells 10 connected in series. The assembled battery 1 according to this embodiment is mounted on an electric vehicle such as a hybrid vehicle, and is used as a power source for driving a load such as an inverter or a traveling motor or a power source for various electric devices. In the present embodiment, a lithium ion battery is employed as the battery cell 10.

  The battery state monitoring device 2 is a device that monitors the charge / discharge state of each battery cell 10 of the assembled battery 1 mounted on a vehicle. The battery state monitoring device 2 according to the present embodiment includes a comparison circuit 3, a logic circuit 4, a voltage detection circuit 5, and a microcomputer 6 (hereinafter abbreviated as a microcomputer).

  The comparison circuit 3 is a comparison unit that compares the cell voltage of each battery cell 10 (voltage for each battery cell 10) with a threshold value and outputs the comparison result. Such a comparison circuit 3 includes a first voltage dividing resistor 31, a second voltage dividing resistor 32, a reference voltage source 33, and a comparator 34 for each battery cell 10.

  The voltage dividing resistors 31 and 32 are connected in series between the positive electrode and the negative electrode of each battery cell 10, and a connection point between the voltage dividing resistors 31 and 32 is a non-inverting input terminal (+) of the comparator 34. It is connected to the. For example, the connection point between the first voltage dividing resistor 31 and the second voltage dividing resistor 32 connected to the battery cell 10 indicated by V12 is connected to the non-inverting input terminal (+) of the comparator 34.

  Each reference voltage source 33 generates a threshold value for comparison with the cell voltage. The reference voltage source 33 is connected between the inverting input terminal (−) of the corresponding comparator 34 and the negative electrode side of the battery cell 10. The threshold value is set to a voltage value for detecting overcharge or overdischarge of the battery cell 10.

  Each comparator 34 is a comparator that detects overcharge or overdischarge by comparing the magnitude relationship between the cell voltage of the corresponding battery cell 10 and the threshold value. Actually, the comparator 34 compares the divided voltage of the first voltage dividing resistor 31 and the second voltage dividing resistor 32 with the threshold value.

  In the comparison circuit 3 having such a configuration, it is not necessary to detect the cell voltage, so that the abnormality of the battery cell 10 can be detected in a short time. However, since the comparison circuit 3 cannot detect the cell voltage, it cannot be used, for example, for calculating the remaining capacity SOC or internal resistance of the battery cell 10 and lacks versatility.

  In the comparison circuit 3 of the present embodiment, for example, when the cell voltage of the battery cell 10 is larger than a threshold value (in the case of overcharge), the comparator 34 outputs a low signal indicating an abnormal state of the battery cell 10. On the other hand, when the cell voltage of the battery cell 10 is smaller than the threshold value, the comparator 34 outputs a high signal indicating the normal state of the battery cell 10.

  Hereinafter, in the present embodiment, the comparison circuit 3 will be described as a configuration in which each comparator 34 detects overcharge. That is, the comparison circuit 3 determines whether or not the battery cell 10 is overcharged, and outputs the determination result (comparison result) to the logic circuit 4 described later for each battery cell 10.

  The logic circuit 4 of the present embodiment is configured by an AND circuit (logical product circuit). The logic circuit 4 is connected to the output terminal of each comparator 34, and outputs an abnormal signal when an abnormal signal (low signal) indicating overcharge is output from at least one of the comparators 34.

  Here, the logic circuit 4 is connected to the microcomputer 6 via the insulating element 71, and the comparison result in the comparison circuit 3 is output from the logic circuit 4 to the microcomputer 6 via the insulating element 71. The insulating element 71 is an element for insulating the high voltage system configured by the assembled battery 1, the comparison circuit 3, the logic circuit 4, and the voltage detection circuit 5 from the low voltage system configured by the microcomputer 6 and the like. It is. As the insulating element 71, for example, a photorelay or a photocoupler having an insulating function can be employed.

  Next, the voltage detection circuit 5 constitutes voltage detection means for detecting voltage information (cell voltage) of each battery cell 10, and includes a cell selection switch (cell selection SW) 51, a differential amplifier circuit 52, and an AD converter. 53 (ADC).

  The cell selection switch 51 is a switch group that connects any one of the battery cells 10 to the differential amplifier circuit 52. The cell selection switch 51 of the present embodiment includes a plurality of positive side switches 51a (SW1_1 to SW12_1) connected to the positive side of each battery cell 10, and a plurality of negative side switches 51b connected to the negative side of the battery cell 10. (SW1_0 to SW12_0). In addition, each of the positive electrode side switch 51a and the negative electrode side switch 51b can be comprised, for example with a transistor.

  One terminal of each positive electrode side switch 51a and one terminal of each negative electrode side switch 51b are connected to the connection point of adjacent battery cells 10, and the other terminal of each positive electrode side switch 51a and each negative electrode side switch 51b The other terminal is connected to the differential amplifier circuit 52. In addition, only the positive electrode side switch 51a (SW12_1) is connected to the positive electrode side of the battery cell 10 on the highest voltage side, and only the negative electrode side switch 51b (SW1_0) is connected to the negative electrode side of the battery cell 10 on the lowest voltage side. Is connected.

  The cell selection switch 51 is controlled to be turned on / off by the microcomputer 6. By controlling the cell selection switch 51 by the microcomputer 6, voltage information of a specific battery cell 10 in the assembled battery 1 and a voltage (block voltage) of a block composed of a predetermined number of battery cells 10 are transferred to the differential amplifier circuit 52. Input is possible.

  The differential amplifier circuit 52 is a circuit that amplifies the voltage of the battery cell 10 selected by the cell selection switch 51, and includes voltage dividing resistors 52a to 52d and an operational amplifier 52e.

  The voltage dividing resistor 52a is connected to the positive switch 51a of the cell selection switch 51, and the voltage dividing resistor 52b is connected between the voltage dividing resistor 52a and the ground. A connection point between the voltage dividing resistors 52a and 52b is connected to a non-inverting input terminal (+) of the operational amplifier 52e.

  The voltage dividing resistor 52c is connected to the negative switch 51b of the cell selection switch 51, and the voltage dividing resistor 52d is connected between the voltage dividing resistor 52c and the output terminal of the operational amplifier 52e. A connection point between the voltage dividing resistors 52c and 52d is connected to the inverting input terminal (−) of the operational amplifier 52e. The output terminal of the operational amplifier 52e is connected to the AD converter 53.

  The AD converter 53 is a circuit that measures the voltage information of the battery cell 10 amplified by the differential amplifier circuit 52, converts the voltage information (analog signal) of the battery cell 10 into a digital signal, and outputs the digital signal to the microcomputer 6. To do.

  Here, the AD converter 53 is connected to the microcomputer 6 via the insulating element 72, and voltage information of the battery cell 10 is output from the AD converter 53 to the microcomputer 6 via the insulating element 72. The insulating element 72 is an element for insulating the high voltage system and the low voltage system, like the insulating element 71.

  Since the voltage detection circuit 5 configured in this way can detect the voltage information (cell voltage) of the battery cell 10 with high accuracy, it can accurately carry out fine abnormality processing when the abnormality of the battery cell 10 is detected. be able to. Moreover, since it can be used for the use which calculates the remaining capacity SOC and internal resistance of the battery cell 10, versatility is high. However, in the voltage detection circuit 5, since it takes time to detect the battery cell 10 and AD conversion, it takes a long time to detect the abnormality, and even if the abnormality can be detected, the battery cell 10 is overcharged or overdischarged. There is a risk of inviting.

  The microcomputer 6 includes a CPU, a ROM, an EEPROM, a RAM, and the like (not shown), and is a control unit that controls the operation of various control objects and performs arithmetic processing according to a program stored in the ROM.

  The microcomputer 6 is compared via the monitoring circuit 61 and the logic circuit 4 as monitoring means for monitoring the charge / discharge state of the battery cell 10 according to the output of at least one of the comparison circuit 3 and the voltage detection circuit 5. The communication processing unit 62 is connected to the circuit 3 and the voltage detection circuit 5.

  The monitoring processing unit 61 performs abnormal processing (fail-safe processing) due to power saving or the like of the battery cell 10 when a low signal is output from the comparison circuit 3 side (logic circuit 4) and an abnormal voltage is output from the voltage detection circuit 5. )I do. As described above, in the present embodiment, the comparison circuit 3 is configured to detect overcharge. Therefore, in the monitoring processing unit 61 of the microcomputer 6, an abnormal signal (low level) from the comparison circuit 3 side (logic circuit 4) is detected. The overcharge of each battery cell 10 is monitored based on whether or not the signal is output.

  In the monitoring processing unit 61 of the present embodiment, when voltage information of each battery cell 10 is input from the voltage detection circuit 5, the voltage information of the battery cell 10 is once stored in a register of the CPU, and then the stored data is read. Perform various calculations with.

  The communication processing unit 62 is connected to the monitoring processing unit 61, and gives priority to the comparison result output from the comparison circuit 3 over the voltage information output from the voltage detection circuit 5 and outputs it to the monitoring processing unit 61. Therefore, the communication processing unit 62 of the microcomputer 6 constitutes an output unit that outputs the comparison result output from the comparison circuit 3 to the monitoring processing unit 61 rather than the voltage information output from the voltage detection circuit 5.

  Specifically, the communication processing unit 62 outputs the comparison result output timing (interrupt) from the comparison circuit 3 side (logic circuit 4) to the microcomputer 6 and the output timing (interrupt) of the voltage information detected by the voltage detection circuit 5. ), The storage and reading of the voltage information detected by the voltage detection circuit 5 is stopped, and the output (comparison result) on the comparison circuit 3 side is output to the monitoring processing unit 61.

  Next, the operation of the battery state monitoring device 2 of the present embodiment will be described with reference to FIG. FIG. 2 is an explanatory diagram for explaining the operation of the battery state monitoring device 2. 2A shows a case where the output timing on the comparison circuit 3 side and the output timing of the voltage detection circuit 5 do not overlap, and FIG. 2B shows the output timing on the comparison circuit 3 side and the output of the voltage detection circuit 5. The case where the timing is heavy is shown.

  In the monitoring processing unit 61 of the microcomputer 6, based on the comparison result output from the comparison circuit 3 side (logic circuit 4) via the communication processing unit 62 and the voltage information output from the voltage detection circuit 5, the battery cell 10 Monitor charge / discharge. At this time, in the communication processing unit 62, when the output timing of the comparison result output from the comparison circuit 3 side (logic circuit 4) and the output timing of the voltage information output from the voltage detection circuit 5 do not overlap, the output timing is early. The output (comparison result or voltage information) is output to the monitoring processor 61 in order.

  For example, as shown in FIG. 2A, when the output timing of the voltage information output from the voltage detection circuit 5 is earlier than the output timing of the comparison result output from the comparison circuit 3 side, the communication processing unit 62 The voltage information output from the voltage detection circuit 5 is prioritized and output to the monitoring processor 61. When voltage information is output from the voltage detection circuit 5 (T1), the monitoring processing unit 61 stores the voltage information from the voltage detection circuit 5 in a register of the CPU and reads the stored voltage information (T2). . Thereafter, when the comparison result from the comparison circuit 3 side is output (T3), the monitoring processing unit 61 stores the comparison result output from the comparison circuit 3 side in a storage means such as a RAM.

  On the other hand, when the output timing of the comparison result output from the comparison circuit 3 side (logic circuit 4) and the output timing of the voltage information output from the voltage detection circuit 5 overlap, the communication processing unit 62 starts from the voltage detection circuit 5 The comparison result output from the comparison circuit 3 side is prioritized and output to the monitoring processor 61 over the output voltage information.

  For example, as shown in FIG. 2B, when the output timing of the voltage detection circuit 5 and the output timing from the comparison circuit 3 side overlap, the communication processing unit 62 monitors the voltage information from the voltage detection circuit 5. The output to the unit 61 is stopped, and the comparison result output from the comparison circuit 3 side is preferentially output to the monitoring processing unit 61. When the voltage information is output from the voltage detection circuit 5 (T1), the monitoring processor 61 starts storing and reading the voltage information from the voltage detection circuit 5 in the CPU register. When the comparison result is output from the comparison circuit 3 side from the time T1 until the storage and reading of the voltage information from the voltage detection circuit 5 is completed (T4), the monitoring processing unit 61 starts from the voltage detection circuit 5. Reading of the voltage information is stopped, and reading of the comparison result from the comparison circuit 3 side is started. When reading of the comparison result from the comparison circuit 3 side is completed (T5), storage and reading of voltage information from the voltage detection circuit 5 is immediately resumed (T5).

  Here, in the microcomputer 6, when the comparison result from the comparison circuit 3 side is an abnormal signal (low signal) indicating an abnormal state (overcharge) of the battery cell 10, the output from the voltage detection circuit 5 side is not read. The abnormality processing (fail safe processing) is executed by the monitoring processing unit 61.

  When the voltage information from the voltage detection circuit 5 is read and the read voltage information is outside the normal range (for example, 3V to 4V) of the battery cell 10, the microcomputer 6 performs an abnormal process (fail-safe). ). In addition, when the voltage information output from the AD converter 53 is displayed on an 8-bit scale in which 3V, which is within the normal range of the battery cell 10, is “10011001” and 4V is “11001100”, “10011001” is displayed on the microcomputer 6 side. When a value (for example, “0001001”) that deviates from “11001100” is output, the microcomputer 6 determines that the voltage is abnormal and executes abnormal processing.

  According to the present embodiment described above, since the comparison circuit 3 is provided, the abnormality of the battery cell 10 can be detected in a short time based on the comparison result output from the comparison circuit 3 side. In addition, since the voltage detection circuit 5 is provided, it is possible to execute extremely detailed abnormality processing when abnormality of the battery cell 10 is detected based on voltage information output from the voltage detection circuit 5.

  Further, when the output timing of the voltage detection circuit 5 and the output timing from the comparison circuit 3 side (logic circuit 4) overlap, the communication processing unit 62 of the microcomputer 6 performs the comparison circuit 3 side (logic circuit 4). The comparison results from are preferentially output to the monitoring processor 61. Thereby, abnormality of the battery cell 10 can be detected rapidly, and it becomes possible to aim at appropriate protection of each battery cell 10 and its peripheral devices.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. In the present embodiment, description of the same or equivalent parts as in the first embodiment will be omitted or simplified.

  FIG. 3 is a schematic configuration diagram of a battery monitoring system including the battery state monitoring device 2 according to the present embodiment. Note that the specific configurations of the comparison circuit 3, the cell selection switch 51, and the differential amplifier circuit 52 shown in FIG. 3 are the same as those in FIG. .

  As shown in FIG. 3, each of the logic circuit 4 and the voltage detection circuit 5 is connected to the management circuit 8. Therefore, the comparison result from the comparison circuit 3 side (logic circuit 4) and the voltage information from the voltage detection circuit 5 are input to the management circuit 8.

  The management circuit 8 outputs the comparison result output from the comparison circuit 3 side and the voltage information output from the voltage detection circuit 5 to the microcomputer 6 via the insulating element 73. The insulating element 73 is the same element as the insulating elements 71 and 72 described in the first embodiment.

  More specifically, the management circuit 8 has a function equivalent to that of the communication processing unit 62 provided in the microcomputer 6 in the first embodiment. That is, the management circuit 8 compares the output timing of the comparison result from the comparison circuit 3 side (logic circuit 4) to the microcomputer 6 side with the output timing of the voltage information detected by the voltage detection circuit 5 The comparison result from the circuit 3 side (logic circuit 4) is preferentially output to the microcomputer 6. In the present embodiment, the management circuit 8 constitutes the output means of the present invention.

  For example, even if the voltage information from the AD converter 53 is being output to the microcomputer 6, the management circuit 8 receives the voltage from the AD converter 53 when the comparison result from the comparison circuit 3 side (logic circuit 4) is input. The output of information is stopped, and the comparison result from the comparison circuit 3 side is preferentially output to the microcomputer.

  Next, the operation of the battery state monitoring device 2 of the present embodiment will be described with reference to FIG. FIG. 4 is an explanatory diagram for explaining the operation of the battery state monitoring device 2 of the present embodiment. 4A shows a case where the output timing on the comparison circuit 3 side and the output timing of the voltage detection circuit 5 do not overlap, and FIG. 4B shows the output timing on the comparison circuit 3 side and the output of the voltage detection circuit 5. The case where timing overlaps is shown.

  The monitoring processing unit 61 of the microcomputer 6 charges the battery cell 10 based on the comparison result output from the comparison circuit 3 side (logic circuit 4) via the management circuit 8 and the voltage information output from the voltage detection circuit 5. Monitor the discharge. At this time, in the management circuit 8, when the output timing of the comparison result from the comparison circuit 3 side (logic circuit 4) and the output timing of the voltage information from the voltage detection circuit 5 do not overlap, an output with an earlier output timing (comparison The result or voltage information is output to the microcomputer 6 in order.

  For example, as shown in FIG. 4A, when the output timing of the voltage detection circuit 5 is earlier than the output timing from the comparison circuit 3, the management circuit 8 gives priority to the voltage information from the voltage detection circuit 5, and the microcomputer 6 (T1). Thereafter, when the comparison result from the comparison circuit 3 side is input (T2), the management circuit 8 outputs the comparison result from the comparison circuit 3 to the microcomputer 6. When the comparison result from the comparison circuit 3 is a low signal indicating an abnormal state of the battery cell 10, the management circuit 8 outputs a signal that has been in a low state for a predetermined period to the microcomputer 6.

  On the other hand, in the management circuit 8, when the output timing of the comparison result from the comparison circuit 3 side (logic circuit 4) and the output timing of the voltage information from the voltage detection circuit 5 overlap, the comparison result from the comparison circuit 3 side. Is output to the microcomputer 6 with priority.

  For example, as shown in FIG. 4B, when the output timing of the voltage detection circuit 5 and the output timing from the comparison circuit 3 side overlap, the voltage information from the voltage detection circuit 5 is output to the management circuit 8 first. Even if (T1), the output processing of the voltage information from the voltage detection circuit 5 to the microcomputer 6 is stopped (T3), and the comparison result from the comparison circuit 3 side is preferentially output to the microcomputer 6.

  The microcomputer 6 monitors the charge / discharge of the battery cell 10 based on the output from the management circuit 8, that is, the comparison result output from the comparison circuit 3 and the voltage information output from the voltage detection circuit 5.

  As in the present embodiment described above, output means for giving priority to the comparison result output from the comparison circuit 3 side over the voltage information output from the voltage detection circuit 5 to the microcomputer 6 is provided separately from the microcomputer 6. You may comprise by the management circuit 8 provided in FIG. Also by this, the same effect as 1st Embodiment can be show | played.

  In the present embodiment, the comparison circuit 3 (logic circuit 4) and the voltage detection circuit 5 are connected to the management circuit 8 arranged in the high voltage system, and the comparison result from the comparison circuit 3 side and the voltage detection circuit 5 are connected. Is output to the microcomputer 6 via the management circuit 8. Therefore, the comparison result output from the comparison circuit 3 side to the microcomputer 6 and the voltage information output from the voltage detection circuit 5 to the microcomputer 6 can be output to the microcomputer 6 via the single management circuit 8. For this reason, it becomes possible to share the output line for outputting an output signal to the microcomputer 6 between the comparison circuit 3 side and the voltage detection circuit 5. In addition, the number of insulating elements 73 that insulate the high voltage system from the low voltage system can be reduced, and the battery state monitoring device 2 can be simplified.

(Other embodiments)
As mentioned above, although embodiment of this invention was described, this invention is not limited to this, Unless it deviates from the range described in each claim, it is not limited to the wording of each claim, and those skilled in the art Improvements based on the knowledge that a person skilled in the art normally has can be added as appropriate to the extent that they can be easily replaced. For example, various modifications are possible as follows.

  (1) In each of the embodiments described above, the logic circuit 4 is configured by an AND circuit, but the configuration of the logic circuit 4 is not limited to the AND circuit. For example, when the output signal from each comparator 34 that is input as the logic circuit 4 includes a low signal indicating an abnormal state of the battery cell 10, information for specifying the battery cell 10 corresponding to the comparator that has output the low signal. It is good also as a structure which produces | generates. In this case, the logic circuit 4 outputs to the microcomputer 6 specific identification information for identifying the battery cell 10 that has been compared with the threshold value among the plurality of battery cells 10 based on the output from the comparison circuit 3. Configure the means.

  Specifically, in the logic circuit 4, the output signal from each comparator 34 is converted into specific cell voltage information that identifies the corresponding battery cell 10, and in addition to the output signal from each comparator 34, cell voltage information Is output to the microcomputer 6 side. Then, in the microcomputer 6, the battery cell 10 corresponding to the comparator 34 that outputs a low signal indicating an abnormal state may be specified based on a control map that associates cell voltage information with each battery cell in advance. .

  (2) In the above-described embodiments, the comparison circuit 3 compares and outputs the magnitude relationship between the cell voltage and the threshold value for each battery cell 10, but the present invention is not limited to this. In the comparison circuit 3, for example, the plurality of battery cells 10 may be divided into a plurality of blocks, and the magnitude relationship between the voltage (block voltage) and the threshold value for each block may be compared and output.

  Thus, when the comparison circuit 3 is configured to compare the magnitude relationship between the block voltage and the threshold value, the number of comparators 34 and the like configuring the comparison circuit 3 can be reduced, and thus the comparison circuit 3 is configured simply. be able to.

  (3) In each of the above-described embodiments, the voltage detection circuit 5 detects voltage information for each battery cell 10, but the present invention is not limited to this, and the plurality of battery cells 10 are divided into a plurality of blocks. The voltage for each block (block voltage) may be detected.

  When the block voltage is detected by the voltage detection circuit 5 in this way, the number of cell selection switches 51 and the like constituting the voltage detection circuit 5 can be reduced, so that the voltage detection circuit 5 has a simple configuration. be able to.

  (4) The AD converter 53 described in each of the above embodiments has been described as a circuit for measuring voltage information (cell voltage) of the battery cell 10 amplified by the differential amplifier circuit 52. Is not limited to the measurement of voltage information. As a function of the AD converter 53, for example, a function of measuring temperature information of each battery cell 10 or a current flowing in the circuit may be added.

  (5) In each of the above-described embodiments, the example in which the assembled battery 1 is used as a power source for an inverter, a traveling motor, and various electric devices of an electric vehicle has been described. It can be used as a power source for various electrical devices. Further, the battery cell 10 is not limited to a lithium ion battery, and may be, for example, a lead storage battery or a nickel hydride battery.

1 battery assembly 10 battery cell 3 comparison circuit (comparison means)
4 logic circuit (cell identification means)
5 Voltage detection circuit (voltage detection means)
61 Monitoring processing unit (monitoring means)
62 Communication processing unit (output means)
8 Management circuit (output means)

Claims (5)

In the battery state monitoring device for monitoring the state of the battery cell in an assembled battery configured by connecting a plurality of battery cells in series,
A comparison means for comparing the voltage of the plurality of battery cells with a threshold;
Voltage detecting means for detecting voltage information of the plurality of battery cells;
Monitoring means for monitoring the state of the battery cell based on the comparison result output from the comparison means and the voltage information output from the voltage detection means;
Output means for giving priority to the comparison result over the voltage information and outputting to the monitoring means;
A battery state monitoring device comprising:   The output means outputs the voltage information when the output timing of the comparison result output from the comparison means to the monitoring means overlaps with the output timing of the voltage information output from the voltage detection means to the monitoring means. The battery state monitoring apparatus according to claim 1, wherein the comparison result is output to the monitoring unit with priority over the comparison result.   And a cell specifying unit that outputs, to the monitoring unit, unique identification information that identifies a battery cell that has been compared with the threshold value among the plurality of battery cells based on an output from the comparing unit. The battery state monitoring device according to claim 1 or 2.   The comparison means outputs an abnormal signal indicating an abnormality of the battery cell as the comparison result when the voltage of the plurality of battery cells is equal to or higher than the threshold value or lower than the threshold value. The battery state monitoring device according to any one of 1 to 3. Each of the comparison means and the voltage detection means is connected to the output means,
5. The battery state monitoring device according to claim 1, wherein the monitoring unit is connected to the comparison unit and the voltage detection unit via the output unit.

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