JP2006029923A - Battery pack charge state detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charge state detector capable of detecting a disconnection between a cell constituting a battery pack and an overcharge detection circuit for detecting abnormality of the cell. <P>SOLUTION: The charge state detector of this invention is constituted of a plurality of overcharge detection circuits and an OR circuit. The input impedances of the overcharge detection circuit connected with a neighboring cell are set to different values with each other. When a disconnection occurs between the cell and the overcharge detection circuit, a voltage corresponding to the overcharge state is impressed to one overcharge detection circuit because of difference of the input impedances with each other. The OR circuit can detect the disconnection between the cell and the overcharge detection circuit from the output of the overcharge detection circuit. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an assembled battery charge state detecting device for detecting a charged state of an assembled battery.

  2. Description of the Related Art Conventionally, as an assembled battery charge state detection device that can detect the state of charge of an assembled battery and also detect failure and abnormality of the device, there is a charge state detection device disclosed in Japanese Patent Laid-Open No. 2003-32907. . This state of charge detection device includes an overcharge determination circuit and an overdischarge determination circuit that are respectively connected to a plurality of unit cells that constitute an assembled battery.

  The overcharge determination circuit is a circuit that outputs a high level when the voltage of the unit cell to be connected is higher than the upper limit value of the allowable voltage range, and includes a constant voltage circuit, a voltage dividing circuit, and a comparator. . The constant voltage circuit is a circuit that outputs a reference voltage corresponding to the upper limit value of the allowable voltage range. The voltage dividing circuit is a circuit that divides the voltage of the unit cell to which the overcharge determination circuit is connected, and includes a voltage dividing resistor and a switch circuit. The voltage dividing resistor is an element for dividing the voltage of the unit cell into a voltage having a magnitude corresponding to the reference voltage. The switch circuit is a circuit that switches the voltage dividing ratio by connecting another resistor in parallel to the voltage dividing resistor when an abnormality of the device is detected. When the voltage of the unit cell is within the allowable voltage range, the switch circuit is set so that the divided voltage of the unit cell is higher than the reference voltage corresponding to the upper limit value of the allowable voltage range. The comparator is a circuit that compares the divided voltage of the unit cell with a reference voltage corresponding to the upper limit value of the allowable voltage range. The comparator outputs a high level when the divided voltage of the unit cell is higher than a reference voltage corresponding to the upper limit value of the allowable voltage range.

  The overdischarge determination circuit is a circuit that outputs a low level when the voltage of the connected unit cell is lower than the lower limit value of the allowable voltage range, and is composed of a constant voltage circuit, a voltage dividing circuit, and a comparator. . The constant voltage circuit is a circuit that outputs a reference voltage corresponding to the lower limit value of the allowable voltage range. The voltage dividing circuit is a circuit that divides the voltage of the unit cell to which the overdischarge determination circuit is connected, and includes a voltage dividing resistor and a switch circuit. The voltage dividing resistor is an element for dividing the voltage of the unit cell into a voltage having a magnitude corresponding to the reference voltage. The switch circuit is a circuit that switches the voltage dividing ratio by connecting another resistor in parallel to the voltage dividing resistor when an abnormality of the device is detected. When the voltage of the unit cell is within the allowable voltage range, the switch circuit is set so that the divided voltage of the unit cell is lower than the reference voltage. The comparator is a circuit that compares the divided voltage of the unit cell with a reference voltage corresponding to the lower limit value of the allowable voltage range. The comparator outputs a low level when the divided voltage of the unit cell is lower than a reference voltage corresponding to the lower limit value of the allowable voltage range.

  When detecting an abnormality in the apparatus, both the overcharge determination circuit and the overdischarge determination circuit switch circuit are turned on. When the voltage of the unit cell is within the allowable voltage range, the voltage of the divided unit cell becomes higher than the reference voltage corresponding to the upper limit value of the allowable voltage range by turning on the switch circuit of the overcharge determination circuit. The comparator of the overcharge determination circuit outputs a high level. In addition, when the switch circuit of the overdischarge determination circuit is turned on, the voltage of the divided unit cell becomes lower than the reference voltage corresponding to the lower limit value of the allowable voltage range, and the comparator of the overdischarge determination circuit has a low level. Output.

As a result, when the overcharge determination circuit does not output a high level, an abnormality occurs in the overcharge determination circuit, and when the overdischarge determination circuit does not output a low level, an abnormality occurs in the overdischarge determination circuit. Can be detected.
JP 2003-32907 A

  By the way, when a disconnection occurs between the unit cell and the overcharge determination circuit and the overdischarge determination circuit, the overcharge determination circuit and the overdischarge determination circuit determine the overcharge state and the overdischarge state based on the voltage of the unit cell. It cannot be detected. For this reason, it is necessary to reliably detect disconnection between the unit cell and the overcharge determination circuit and overdischarge determination circuit. However, the above-described charging state detection device can detect an abnormality in the overcharge determination circuit and the overdischarge determination circuit, but detects a disconnection between the unit cell and the overcharge determination circuit and the overdischarge determination circuit. I can't.

  This invention is made in view of such a situation, and assembled battery charge state detection which can detect the disconnection between the cell which comprises an assembled battery, and the abnormality detection circuit which detects abnormality of a cell An object is to provide an apparatus.

  Therefore, as a result of intensive studies and trial and error to solve this problem, the present inventor has determined that the input impedance of the abnormality detection circuit that detects the abnormality of the cell based on the cell voltage is different for each adjacent cell. As a result, it was conceived that a disconnection between the cell and the abnormality detection circuit can be detected, and the present invention has been completed.

  That is, the assembled battery charge state detection device according to claim 1 includes an abnormality detection circuit that is connected to each of a plurality of cells connected in series constituting the assembled battery and detects an abnormality of the cell based on the voltage of the cell. In the assembled battery charge state detection device, the abnormality detection circuit has different input impedances for each of the adjacent cells connected thereto, and further, the cell and the abnormality detection circuit based on the output of the abnormality detection circuit. And a disconnection detection circuit for detecting disconnection between the two.

  The assembled battery charge state detection device according to claim 2 is the assembled battery charge state detection device according to claim 1, and further, the abnormality detection circuit has a resistance value for each of the adjacent cells connected thereto. A different resistance is provided between input terminals connected to the cell.

  The assembled battery charge state detection device according to claim 3 is the assembled battery charge state detection device according to claim 1, and the abnormality detection circuit further compares the voltage of the cell with an overcharge voltage threshold. When the overcharge state of the cell is detected, the disconnection detection circuit detects a disconnection between the cell and the abnormality detection circuit when the abnormality detection circuit detects the overcharge state of the cell. It is determined that it is present.

  The assembled battery charge state detection device according to claim 4 is the assembled battery charge state detection device according to claim 1, and further, the abnormality detection circuit compares the voltage of the cell with an overdischarge voltage threshold. Thus, the overdischarge state of the cell is detected, and the disconnection detection circuit has a disconnection between the cell and the abnormality detection circuit when the abnormality detection circuit detects an overdischarge state of the cell. It is characterized by determining.

  The assembled battery charge state detection device according to claim 5 is the assembled battery charge state detection device according to claim 1 or 2, wherein the abnormality detection circuit further converts the voltage of the cell into an overcharge voltage threshold value and an overdischarge voltage. The overcharged state and overdischarged state of the cell are detected by comparing with a voltage threshold, and the disconnection detection circuit detects whether the overcharged state of the cell is detected by one of the abnormality detection circuits connected to the adjacent cells. And when the other detects an overdischarge state of the cell, it is determined that a disconnection has occurred between the connection point between the adjacent cells and the abnormality detection circuit.

  The assembled battery charge state detection device according to claim 6 is the assembled battery charge state detection device according to any one of claims 1 to 5, further detecting a charge state of the assembled battery mounted on a vehicle. To do.

  According to the assembled battery charge state detection device of the first aspect, the disconnection that occurs between the cell and the abnormality detection circuit can be detected as a cell abnormality. Therefore, the reliability of the assembled battery charge state detection device can be improved.

  When a disconnection occurs between the connection points of adjacent cells and the abnormality detection circuit connected to those cells, the abnormality detection circuit divides all voltages of adjacent cells by a voltage division ratio determined by the mutual input impedance. A pressed voltage is applied. Since the input impedance of the abnormality detection circuit connected to the adjacent cell is set to a different value, the voltage applied to the abnormality detection circuit is different from the voltage of the cell applied before disconnection. . Therefore, the abnormality detection circuit can detect a disconnection occurring between the cell and the abnormality detection circuit as a cell abnormality. The disconnection detection circuit can detect disconnection based on the output of the abnormality detection circuit.

  According to the assembled battery charge state detection device of the second aspect, the input impedance of the abnormality detection circuit connected to the adjacent cell can be reliably set to a different value.

  According to the assembled battery charge state detection device according to the third aspect, the disconnection generated between the cell and the abnormality detection circuit can be detected as the overcharge state of the cell. Therefore, the reliability of the assembled battery charge state detection device can be reliably improved.

  According to the assembled battery charge state detection device of the fourth aspect, the disconnection generated between the cell and the abnormality detection circuit can be detected as the overdischarge state of the cell. Therefore, the reliability of the assembled battery charge state detection device can be reliably improved.

  According to the assembled battery charge state detection device of the fifth aspect, it is possible to identify the occurrence location of the disconnection between the cell and the abnormality detection circuit from the occurrence state of the overcharge state and the overdischarge state of the cell. Therefore, the reliability of the assembled battery charge state detection device can be further improved.

  According to the assembled battery charge state detection device of the sixth aspect, in the vehicle, it is possible to detect disconnection between the cells constituting the assembled battery and the abnormality detection circuit that detects abnormality of the cells. Therefore, the reliability of the assembled battery charge state detection device mounted on the vehicle can be improved.

  In this embodiment, the assembled battery charge state detection device according to the present invention is applied to an assembled battery system that has an assembled battery that supplies power to a drive motor of a hybrid electric vehicle and outputs data related to the state of the assembled battery. An example is shown.

(First embodiment)
The block diagram of the assembled battery system in 1st Embodiment is shown in FIG. 1, and the circuit diagram of a charge condition detection apparatus is shown in FIG. Then, with reference to FIG. 1 and FIG. 2, a specific description will be given in the order of configuration, operation, and effect.

  First, the configuration of the assembled battery system will be described. As shown in FIG. 1, the assembled battery system 1 includes an assembled battery 10, charge state detection devices CMU <b> 1 to CMUn (assembled battery charge state detection device), a current sensor 11, and an assembled battery controller 12. . A hybrid electric vehicle controller 2 (hereinafter referred to as HEV controller) is connected to the assembled battery controller 12. Furthermore, a motor 4 is connected to the HEV controller 2 via an inverter 3.

  The assembled battery 10 is, for example, a direct current power source configured by connecting n sets of cell groups CG1 to CGn including six chargeable / dischargeable cells in series. The positive electrode terminal and the negative electrode terminal of the assembled battery 10 are each connected to the inverter 3.

  The charge state detection devices CMU1 to CMUn are devices that are provided for the corresponding cell groups CG1 to CGn, respectively, and detect the charge states of the individual cells constituting the cell groups CG1 to CGn. The input terminals of the charge state detection devices CMU1 to CMUn are connected to the positive and negative terminals of the individual cells constituting the corresponding cell groups CG1 to CGn, and the output terminals are connected to the assembled battery controller 12, respectively.

  The current sensor 11 is a sensor that detects a current flowing through the assembled battery 10. The current sensor 11 is disposed between the negative terminal of the assembled battery 10 and the inverter 3, and the output terminal of the current sensor 11 is connected to the assembled battery controller 12.

  The assembled battery controller 12 is a device that outputs data related to the state of the assembled battery 10 based on the voltages of the cell groups CG1 to CGn, the outputs of the charging state detection devices CMU1 to CMUn, and the current flowing through the assembled battery 10. Input terminals of the battery pack controller 12 are connected to the positive and negative terminals of the cell groups CG1 to CGn, the output terminals of the charge state detection devices CMU1 to CMUn, and the output terminal of the current sensor 11, respectively. The output terminal is connected to the HEV controller 2.

  Next, a specific configuration of the charge state detection devices CMU1 to CMUn will be described in detail. Since the charging state detection devices CMU1 to CMUn have the same configuration, only the charging state detection device CMU1 will be described here.

  As shown in FIG. 2, the charging state detection device CMU1 includes overcharge detection circuits U11 to U16 (abnormality detection circuit) and an OR circuit OR1 (disconnection detection circuit). The charge state detection device CMU1 is connected to a cell group CG1 including six cells C11 to C16 connected in series.

  The overcharge detection circuits U11 to U16 are connected to the corresponding cells C11 to C16, respectively, and determine that the cells C11 to C16 are in an overcharged state when the voltage of the cells C11 to C16 is greater than, for example, 4.2V. This circuit outputs a high level.

  The overcharge detection circuit U11 includes a cell voltage dividing circuit 110, an overcharge determination reference voltage circuit 111, and a comparator 112, and is connected to the cell C11.

  The cell voltage dividing circuit 110 is a circuit that divides and outputs the voltage of the cell C11. The cell voltage dividing circuit 110 includes resistors 110a and 110b. The resistor 110a and the resistor 110b are connected in series. Of the resistors 110a and 110b connected in series, one end of the resistor 110a is connected to the positive terminal of the cell C11, and one end of the resistor 110b is connected to the negative terminal of the cell C11.

  The overcharge determination reference voltage circuit 111 is a circuit that outputs an overcharge voltage threshold for determining the presence or absence of an overcharge state in the cell C11, for example, a reference voltage corresponding to a cell voltage of 4.2V. The overcharge determination reference voltage circuit 111 includes a resistor 111a and an overcharge determination reference power supply 111b. One end of the resistor 111a is connected to the positive terminal of the cell C11, the other end is connected to the positive terminal of the overcharge determination reference power supply 111b, and the negative terminal of the overcharge determination reference power supply 111b is connected to the negative terminal of the cell C11. Yes.

  The comparator 112 is an element that compares the voltage of the cell C11 divided by the cell voltage dividing circuit 110 with the reference voltage output from the overcharge determination reference voltage circuit 111. The comparator 112 outputs a high level when the divided voltage of the cell C11 is higher than a reference voltage corresponding to the overcharge voltage threshold. The non-inverting input terminal of the comparator 112 is a connection point between the resistors 110a and 110b of the cell voltage dividing circuit 110, and the inverting input terminal is a connection between the resistor 111a of the overcharge determination reference voltage circuit 111 and the reference power source 111b for overcharge determination. Each point is connected. The output terminal is connected to the input terminal of the OR circuit OR1.

  An overcharge detection circuit U12 is connected to the cell C12 adjacent to the cell C11. The overcharge detection circuit U12 includes a cell voltage dividing circuit 120, an overcharge determination reference voltage circuit 121, and a comparator 122.

  The cell voltage dividing circuit 120 is a circuit that divides and outputs the voltage of the cell C12. The cell voltage dividing circuit 120 includes resistors 120a and 120b. The resistor 120a and the resistor 120b are connected in series. Of the resistors 120a and 120b connected in series, one end of the resistor 120a is connected to the positive terminal of the cell C12, and one end of the resistor 120b is connected to the negative terminal of the cell C12.

  The overcharge determination reference voltage circuit 121 is a circuit that outputs an overcharge voltage threshold for determining the presence or absence of an overcharge state in the cell C12, for example, a reference voltage corresponding to a cell voltage of 4.2V. The overcharge determination reference voltage circuit 121 includes a resistor 121a and an overcharge determination reference power supply 121b. One end of the resistor 121a is connected to the positive terminal of the cell C12, the other end is connected to the positive terminal of the overcharge determination reference power supply 121b, and the negative terminal of the overcharge determination reference power supply 121b is connected to the negative terminal of the cell C12. Yes.

  The comparator 122 is an element that compares the voltage of the cell C12 divided by the cell voltage dividing circuit 120 with the reference voltage output from the overcharge determination reference voltage circuit 121. The comparator 122 outputs a high level when the divided voltage of the cell C12 is higher than a reference voltage corresponding to the overcharge voltage threshold. The non-inverting input terminal of the comparator 122 is a connection point between the resistors 120a and 120b of the cell voltage dividing circuit 120, and the inverting input terminal is a connection between the resistor 121a of the overcharge determination reference voltage circuit 121 and the reference power source 121b for overcharge determination. Each point is connected. The output terminal is connected to another input terminal of the OR circuit OR1.

  Here, the cell voltage divider circuit 120 of the overcharge detection circuit U12 has a voltage division ratio equal to the voltage division ratio of the cell voltage divider circuit 110 of the overcharge detection circuit U11, and the combined resistance value is the overcharge detection circuit. It is set to be larger than the combined resistance value of the cell voltage dividing circuit 110 of U11. The overcharge determination reference voltage circuit 111 of the overcharge detection circuit U11 and the overcharge determination reference power supply circuit 121 of the overcharge detection circuit U12 include the resistance values of the resistors 111a and 121a and the overcharge determination reference power supply 111b. The internal resistance values of the overcharge determination reference power supply 121b are set to be equal to each other. Further, the comparator 112 of the overcharge detection circuit U11 and the comparator 122 of the overcharge detection circuit U12 are set so that their input impedances are equal to each other. That is, the overcharge detection circuit U12 is set to have a larger input impedance than the overcharge detection circuit U11.

  Overcharge detection circuits U13 to U16 are connected to the cells C13 to C16, respectively. Since the overcharge detection circuits U13 and U15 are the same circuits as the overcharge detection circuit U11, and the overcharge detection circuits U14 and U16 are the same circuits as the overcharge detection circuit U12, description thereof will be omitted.

  The OR circuit OR1 detects the overcharge state of the cells C11 to C16 based on the outputs of the overcharge detection circuits U11 to U16, and detects a disconnection between the cells C11 to C16 and the overcharge detection circuits U11 to U16. Circuit. The OR circuit OR1 is high when at least one of the cells C11 to C16 is in an overcharge state or when a disconnection occurs in at least one of the cells C11 to C16 and the overcharge detection circuits U11 to U16. Output level. The six input terminals of the OR circuit OR1 are connected to the comparators 112, 122, 132, 142, 152, 162 of the overcharge detection circuits U11 to U16, respectively. The output terminal is connected to the battery pack controller 12.

  Next, a specific operation will be described with reference to FIGS. The hybrid electric vehicle travels with the driving force of the engine during constant speed traveling with high engine operating efficiency. As shown in FIG. 1, at this time, when the charge amount of the assembled battery 10 is insufficient, the motor 4 functions as a generator by rotating by the driving force of the engine, and the assembled battery 10 is connected via the inverter 3. To charge. On the other hand, the hybrid electric vehicle travels by using the driving force of the motor 4 generated by the electric power supplied from the assembled battery 10 via the inverter 3 at the time of start-up and full acceleration when the operation efficiency of the engine is low. .

  The assembled battery system 1 supplies power from the assembled battery 10, and based on the voltages of the cell groups CG1 to CGn constituting the assembled battery 10, the outputs of the charge state detection devices CMU1 to CMUn, and the current flowing through the assembled battery 10, Data on the state of the assembled battery 10 is output. The HEV controller 2 appropriately controls the motor 4 via the inverter 3 based on data regarding the state of the assembled battery 10 output from the assembled battery system 1.

  As shown in FIG. 2, for example, when the voltage of the cell C11 becomes larger than the overcharge voltage threshold value of 4.2V, the voltage of the cell C11 is divided by the cell voltage dividing circuit 110 of the overcharge detection circuit U11. The The voltage of the cell C11 divided by the cell voltage dividing circuit 110 is compared with the reference voltage output from the overcharge determination reference voltage circuit 111 by the comparator 112. Since the voltage of the cell C11 is larger than the overcharge voltage threshold, the comparator 112 outputs a high level. When the output of the comparator 112 of the overcharge detection circuit U11 becomes high level, the OR circuit OR1 outputs high level.

  On the other hand, for example, when a disconnection occurs at a point A between the connection points of the cells C11 and C12 and the overcharge detection circuits U11 and U12, all the voltages of the cells C11 and C12 connected in series are Is applied to the overcharge detection circuits U11 and U12 connected in series.

  By the way, the input impedance of the overcharge detection circuit U12 is set to be larger than the input impedance of the overcharge detection circuit U11. Therefore, a voltage higher than the voltage of the cell C12 determined by the ratio of the input impedances of the overcharge detection circuits U11 and U12 is applied between the input terminals of the overcharge detection circuit U12. The voltage between the input terminals of the overcharge detection circuit U12 can be set to a voltage higher than the overcharge voltage threshold value by optimally setting the input impedance of the overcharge detection circuits U11 and U12.

  The voltage between the input terminals of the overcharge detection circuit U12 is divided by the cell voltage dividing circuit 120. The voltage between the input terminals of the overcharge detection circuit U12 divided by the cell voltage divider circuit 120 is compared with the reference voltage output from the overcharge determination reference voltage circuit 121 by the comparator 122. Since the voltage between the input terminals of the overcharge detection circuit U12 is larger than the overcharge voltage threshold, the comparator 122 outputs a high level. When the output of the comparator 122 of the overcharge detection circuit U12 becomes high level, the OR circuit OR1 outputs high level.

  Thereby, the disconnection which generate | occur | produced between cell C11, C12 and overcharge detection circuit U11, U12 is detectable as an overcharge state. Similarly, disconnection between the cells C12 to C16 and the overcharge detection circuits U12 to U16 can be detected as an overcharged state of any cell.

  Finally, specific effects will be described. According to the present embodiment, the charge state detection device CMU1 can detect a disconnection that occurs between the cells C11 to C16 and the overcharge detection circuits U11 to U16 as an overcharge state of the cell. Therefore, the reliability of the charge state detection device CMU1 and the charge state detection devices CMU2 to CMUn having the same circuit configuration can be improved.

  In addition, the charge state detection device CMU1 sets the combined resistance value of the cell voltage dividing circuit to different values in the overcharge detection circuit connected to the adjacent cell, thereby overcharging connected to the adjacent cell. The input impedance of the detection circuit can be reliably set to different values.

  Furthermore, the charge state detection device CMU1 detects a disconnection between the cells C11 to C16 constituting the assembled battery 10 and the overcharge detection circuits U11 to U16 that detect the overcharge states of the cells C11 to C16 in the vehicle. be able to. Therefore, the reliability of the charge state detection device CMU1 of the assembled battery 10 mounted on the vehicle and the charge state detection devices CMU2 to CMUn having the same circuit configuration can be improved.

  In the above-described embodiment, in the overcharge detection circuit connected to the adjacent cell, the combined resistance value of the cell voltage dividing circuit is set to a different value. It is not a thing. For example, as shown in FIG. 3, a resistor 113 is connected between the input terminals of the overcharge detection circuit U11 separately from the cell voltage voltage dividing circuit 110, and the resistance value of this resistor is connected to an adjacent cell. Different values may be set for each detection circuit. In this case, in all overcharge detection circuits, the cell voltage dividing circuit, the overcharge determination reference voltage circuit, and the comparator can be shared, and an increase in the types of components constituting the circuit can be suppressed.

(Second Embodiment)
Next, FIG. 4 shows a circuit diagram of the charging state detection apparatus in the second embodiment. Here, the charge state detection devices CMU1 to CMUn, which are different from the assembled battery system 1 in the first embodiment, will be described, and the description of the common portions other than the necessary portions will be omitted. In addition, the same code | symbol is attached | subjected and demonstrated to the element same as the said embodiment.

  First, specific configurations of the charge state detection devices CMU1 to CMUn will be described in detail. Since the charging state detection devices CMU1 to CMUn have the same configuration, only the charging state detection device CMU2 will be described here.

  As shown in FIG. 4, the charging state detection device CMU2 includes overdischarge detection circuits L21 to L26 (abnormality detection circuit) and an AND circuit AND2 (disconnection detection circuit). The charging state detection device CMU2 is connected to a cell group CG2 including six cells C21 to C26 connected in series.

  The overdischarge detection circuits L21 to L26 are connected to the corresponding cells C21 to C26, respectively, and when the voltages of the cells C21 to C26 are smaller than, for example, 3.0 V, the cells C21 to C26 are determined to be in an overdischarge state. This circuit outputs a low level.

  The overdischarge detection circuit L21 includes a cell voltage dividing circuit 210, an overdischarge determination reference voltage circuit 211, and a comparator 212, and is connected to the cell C21.

  The cell voltage dividing circuit 210 is a circuit that divides and outputs the voltage of the cell C21. The cell voltage dividing circuit 210 includes resistors 210a and 210b. The resistors 210a and 210b are connected in series. Of the resistors 210a and 210b connected in series, one end of the resistor 210a is connected to the positive terminal of the cell C21, and one end of the resistor 210b is connected to the negative terminal of the cell C21.

  The overdischarge determination reference voltage circuit 211 is a circuit that outputs an overdischarge voltage threshold for determining the presence or absence of an overdischarge state in the cell C21, for example, a reference voltage corresponding to a cell voltage of 3.0V. The overdischarge determination reference voltage circuit 211 includes a resistor 211a and an overdischarge determination reference power supply 211b. One end of the resistor 211a is connected to the positive terminal of the cell C21, the other end is connected to the positive terminal of the overdischarge determination reference power supply 211b, and the negative terminal of the overdischarge determination reference power supply 211b is connected to the negative terminal of the cell C21. Yes.

  The comparator 212 is an element that compares the voltage of the cell C21 divided by the cell voltage dividing circuit 210 with the reference voltage output from the overdischarge determination reference voltage circuit 211. The comparator 212 outputs a low level when the divided voltage of the cell C21 is smaller than the reference voltage corresponding to the overdischarge voltage threshold. The non-inverting input terminal of the comparator 212 is connected to the connection point between the resistors 210a and 210b of the cell voltage divider 210, and the inverting input terminal is connected to the resistor 211a of the overdischarge determination reference voltage circuit 211 and the reference power supply 211b for overdischarge determination. Each point is connected. The output terminal is connected to the input terminal of the AND circuit AND2.

  An overdischarge detection circuit L22 is connected to the cell C22 adjacent to the cell C21. The overdischarge detection circuit L22 includes a cell voltage voltage dividing circuit 220, an overdischarge determination reference voltage circuit 221 and a comparator 222.

  The cell voltage dividing circuit 220 is a circuit that divides and outputs the voltage of the cell C22. The cell voltage dividing circuit 220 includes resistors 220a and 220b. The resistor 220a and the resistor 220b are connected in series. Of the resistors 220a and 220b connected in series, one end of the resistor 220a is connected to the positive terminal of the cell C22, and one end of the resistor 220b is connected to the negative terminal of the cell C22.

  The overdischarge determination reference voltage circuit 221 is a circuit that outputs an overdischarge voltage threshold for determining the presence or absence of an overdischarge state in the cell C22, for example, a reference voltage corresponding to a cell voltage of 3.0V. The overdischarge determination reference voltage circuit 221 includes a resistor 221a and an overdischarge determination reference power supply 221b. One end of the resistor 221a is connected to the positive terminal of the cell C22, the other end is connected to the positive terminal of the overdischarge determination reference power supply 221b, and the negative terminal of the overdischarge determination reference power supply 221b is connected to the negative terminal of the cell C22. Yes.

  The comparator 222 is an element that compares the voltage of the cell C22 divided by the cell voltage dividing circuit 220 with the reference voltage output from the overdischarge determination reference voltage circuit 221. The comparator 222 outputs a low level when the divided voltage of the cell C22 is smaller than the reference voltage corresponding to the overdischarge voltage threshold. The non-inverting input terminal of the comparator 222 is a connection point between the resistors 220a and 220b of the cell voltage dividing circuit 220, and the inverting input terminal is a connection between the resistor 221a of the overdischarge determination reference voltage circuit 221 and the overdischarge determination reference power supply 221b. Each point is connected. The output terminal is connected to another input terminal of the AND circuit AND2.

  Here, the cell voltage divider circuit 210 of the overdischarge detection circuit L21 has a voltage division ratio equal to the voltage division ratio of the cell voltage divider circuit 220 of the overdischarge detection circuit L22, and the combined resistance value is an overdischarge detection circuit. It is set to be smaller than the combined resistance value of the cell voltage dividing circuit 220 of L22. The overdischarge determination reference voltage circuit 211 of the overdischarge detection circuit L21 and the overdischarge determination reference power supply circuit 221 of the overdischarge detection circuit L22 include resistance values of the resistors 211a and 221a and the overdischarge determination reference power supply 211b. The internal resistance values of the overdischarge determination reference power source 221b are set to be equal to each other. Further, the comparator 212 of the overdischarge detection circuit L21 and the comparator 222 of the overdischarge detection circuit L22 are set so that the input impedances are equal to each other. That is, the overdischarge detection circuit L21 is set so that the input impedance is smaller than that of the overdischarge detection circuit L22.

  Overdischarge detection circuits L23 to L26 are connected to the cells C23 to C26, respectively. The overdischarge detection circuits L23 and L25 are the same circuit as the overdischarge detection circuit L21, and the overdischarge detection circuits L24 and L26 are the same circuits as the overdischarge detection circuit L22, respectively, and thus description thereof is omitted.

  The AND circuit AND2 detects the overdischarge state of the cells C21 to C26 based on the outputs of the overdischarge detection circuits L21 to L26, and detects the disconnection between the cells C21 to C26 and the overdischarge detection circuits L21 to L26. Circuit. The AND circuit AND2 is low when at least one of the cells C21 to C26 is in an overdischarge state or when a disconnection occurs in at least one of the cells C21 to C26 and the overdischarge detection circuits L21 to L26. Output level. The six input terminals of the AND circuit AND2 are connected to the comparators 212, 222, 232, 242, 252, and 262 of the overdischarge detection circuits L21 to L26, respectively. The output terminal is connected to the battery pack controller 12.

  Next, a specific operation will be described with reference to FIG. As shown in FIG. 4, for example, when the voltage of the cell C21 becomes lower than the overdischarge voltage threshold value of 3.0 V, the voltage of the cell C21 is divided by the cell voltage dividing circuit 210 of the overdischarge detection circuit L21. The The voltage of the cell C21 divided by the cell voltage dividing circuit 210 is compared with the reference voltage output from the overdischarge determination reference voltage circuit 211 by the comparator 212. Since the voltage of the cell C21 is smaller than the overdischarge voltage threshold, the comparator 212 outputs a low level. When the output of the comparator 212 of the overdischarge detection circuit L21 becomes low level, the AND circuit AND2 outputs low level.

  On the other hand, for example, when a disconnection occurs at a point B between the connection point of the cells C21 and C22 and the overdischarge detection circuits L21 and L22, all the voltages of the cells C21 and C22 connected in series are Is applied to overdischarge detection circuits L21 and L22 connected in series.

  Incidentally, the input impedance of the overdischarge detection circuit L21 is set to be smaller than the input impedance of the overdischarge detection circuit L22. Therefore, a voltage smaller than the voltage of the cell C21 determined by the ratio of the input impedances of the overdischarge detection circuits L21 and L22 is applied between the input terminals of the overdischarge detection circuit L21. The voltage between the input terminals of the overdischarge detection circuit L21 can be set to a voltage lower than the overdischarge voltage threshold value by optimally setting the input impedance of the overdischarge detection circuits L21 and L22.

  The voltage between the input terminals of the overdischarge detection circuit L21 is divided by the cell voltage dividing circuit 210. The voltage between the input terminals of the overdischarge detection circuit L21 divided by the cell voltage divider circuit 210 is compared with the reference voltage output from the overdischarge determination reference voltage circuit 211 by the comparator 212. Since the voltage between the input terminals of the overdischarge detection circuit L21 is smaller than the overdischarge voltage threshold, the comparator 212 outputs a low level. When the output of the comparator 212 of the overdischarge detection circuit L21 becomes low level, the AND circuit AND2 outputs low level.

  Thereby, the disconnection which generate | occur | produced between cell C21, C22 and overdischarge detection circuit L21, L22 is detectable as an overcharge state. Similarly, disconnection between the cells C22 to C26 and the overdischarge detection circuits L22 to L26 can be detected as an overdischarge state of any cell.

  Finally, specific effects will be described. According to the present embodiment, the charge state detection device CMU2 can detect a disconnection that occurs between the cells C21 to C26 and the overdischarge detection circuits L21 to L26 as the overdischarge state of the cell. Therefore, the reliability of the charge state detection device CMU2 and the charge state detection devices CMU1 and CMU3 to CMUn having the same circuit configuration can be improved.

  In addition, the charge state detection device CMU2 sets the combined resistance value of the cell voltage dividing circuit to different values in the overdischarge detection circuit connected to the adjacent cell, thereby connecting the overdischarge connected to the adjacent cell. The input impedance of the detection circuit can be reliably set to different values.

  Further, the charging state detection device CMU2 detects disconnection between the cells C21 to C26 constituting the assembled battery 10 and the overdischarge detection circuits L21 to L26 that detect the overdischarge states of the cells C21 to C26 in the vehicle. be able to. Therefore, the reliability of the charge state detection device CMU2 of the assembled battery 10 mounted on the vehicle and the charge state detection devices CMU1 and CMU3 to CMUn having the same circuit configuration can be improved.

  In the above-described embodiment, in the overdischarge detection circuit connected to the adjacent cell, an example in which the combined resistance value of the cell voltage divider circuit is set to a different value is described. It is not a thing. For example, as shown in FIG. 5, a resistor 213 is connected between the input terminals of the overdischarge detection circuit L21 separately from the cell voltage voltage dividing circuit 210, and the resistance value of this resistor is connected to an adjacent cell. Different values may be set for each detection circuit. In this case, in all overdischarge detection circuits, the cell voltage dividing circuit, the overdischarge determination reference voltage circuit, and the comparator can be shared, and an increase in the types of components constituting the circuit can be suppressed.

(Third embodiment)
Next, FIG. 6 shows a circuit diagram of the charging state detection apparatus in the third embodiment. Here, the charge state detection apparatuses CMU1 to CMUn, which are different from the assembled battery system 1 in the first and second embodiments, will be described, and the description of the common parts other than the necessary parts will be omitted. In addition, the same code | symbol is attached | subjected and demonstrated to the element same as the said embodiment.

  First, specific configurations of the charge state detection devices CMU1 to CMUn will be described in detail. Since the charging state detection devices CMU1 to CMUn have the same configuration, only the charging state detection device CMU3 will be described here.

  As shown in FIG. 5, the charging state detection device CMU3 includes an overcharge / discharge detection circuit UL31 to UL36 (abnormality detection circuit) and a microcomputer CPU3 (disconnection detection circuit). The charge state detection device CMU3 is connected to a cell group CG3 including six cells C31 to C36 connected in series.

  The overcharge / discharge detection circuits UL31 to UL36 are connected to the corresponding cells C31 to C36, respectively, and when the voltages of the cells C31 to C36 are larger than, for example, 4.2V, it is determined that the cells C31 to C36 are in the overcharge state. When the high level is lower than 3.0 V, the cells C31 to C36 are determined to be in an overdischarged state, and the low level is output.

  The overcharge / discharge detection circuit UL31 includes a cell voltage dividing circuit 310, an overcharge determination reference voltage circuit 311, a comparator 312, an overdischarge determination reference voltage circuit 313, and a comparator 314. It is connected.

  The cell voltage dividing circuit 310 is a circuit that divides and outputs the voltage of the cell C31. The cell voltage dividing circuit 310 includes resistors 310a and 310b. The resistor 310a and the resistor 310b are connected in series. Of the resistors 310a and 310b connected in series, one end of the resistor 310a is connected to the positive terminal of the cell C31, and one end of the resistor 310b is connected to the negative terminal of the cell C31.

  The overcharge determination reference voltage circuit 311 is a circuit that outputs an overcharge voltage threshold for determining the presence or absence of an overcharge state in the cell C31, for example, a reference voltage corresponding to a cell voltage of 4.2V. The overcharge determination reference voltage circuit 311 includes a resistor 311a and an overcharge determination reference power supply 311b. One end of the resistor 311a is connected to the positive terminal of the cell C31, the other end is connected to the positive terminal of the overcharge determination reference power supply 311b, and the negative terminal of the overcharge determination reference power supply 311b is connected to the negative terminal of the cell C31. Yes.

  The comparator 312 is an element that compares the voltage of the cell C31 divided by the cell voltage dividing circuit 310 with the reference voltage output from the overcharge determination reference voltage circuit 311. The comparator 312 outputs a high level when the divided voltage of the cell C31 is higher than a reference voltage corresponding to the overcharge voltage threshold. The non-inverting input terminal of the comparator 312 is a connection point between the resistors 310a and 310b of the cell voltage dividing circuit 310, and the inverting input terminal is a connection between the resistor 311a of the overcharge determination reference voltage circuit 311 and the overcharge determination reference power supply 311b. Each point is connected. The output terminal is connected to the input terminal of the microcomputer CPU3.

  The overdischarge determination reference voltage circuit 313 is a circuit that outputs an overdischarge voltage threshold for determining the presence or absence of an overdischarge state in the cell C31, for example, a reference voltage corresponding to a cell voltage of 3.0V. The overdischarge determination reference voltage circuit 313 includes a resistor 313a and an overdischarge determination reference power supply 313b. One end of the resistor 313a is connected to the positive terminal of the cell C31, the other end is connected to the positive terminal of the overdischarge determination reference power supply 313b, and the negative terminal of the overdischarge determination reference power supply 313b is connected to the negative terminal of the cell C31. Yes.

  The comparator 314 is an element that compares the voltage of the cell C31 divided by the cell voltage dividing circuit 310 with the reference voltage output from the overdischarge determination reference voltage circuit 313. The comparator 314 outputs a low level when the divided voltage of the cell C31 is smaller than the reference voltage corresponding to the overdischarge voltage threshold. The non-inverting input terminal of the comparator 314 is connected to the connection point between the resistors 310a and 310b of the cell voltage dividing circuit 310, and the inverting input terminal is connected to the resistor 313a of the overdischarge determination reference voltage circuit 313 and the reference power supply 313b for overdischarge determination. Each point is connected. The output terminal is connected to the input terminal of the microcomputer CPU3.

  An overcharge / discharge detection circuit UL32 is connected to the cell C32 adjacent to the cell C31.

  The overcharge / discharge detection circuit UL32 includes a cell voltage dividing circuit 320, an overcharge determination reference voltage circuit 321, a comparator 322, an overdischarge determination reference voltage circuit 323, and a comparator 324.

  The cell voltage dividing circuit 320 is a circuit that divides and outputs the voltage of the cell C32. The cell voltage dividing circuit 320 includes resistors 320a and 320b. The resistor 320a and the resistor 320b are connected in series. Of the resistors 320a and 320b connected in series, one end of the resistor 320a is connected to the positive terminal of the cell C32, and one end of the resistor 320b is connected to the negative terminal of the cell C32.

  The overcharge determination reference voltage circuit 321 is a circuit that outputs an overcharge voltage threshold for determining the presence or absence of an overcharge state in the cell C32, for example, a reference voltage corresponding to a cell voltage of 4.2V. The overcharge determination reference voltage circuit 321 includes a resistor 321a and an overcharge determination reference power supply 321b. One end of the resistor 321a is connected to the positive terminal of the cell C32, the other end is connected to the positive terminal of the overcharge determination reference power supply 321b, and the negative terminal of the overcharge determination reference power supply 321b is connected to the negative terminal of the cell C32. Yes.

  The comparator 322 is an element that compares the voltage of the cell C32 divided by the cell voltage dividing circuit 320 with the reference voltage output from the overcharge determination reference voltage circuit 321. The comparator 322 outputs a high level when the divided voltage of the cell C32 is higher than a reference voltage corresponding to the overcharge voltage threshold. The non-inverting input terminal of the comparator 322 is connected to the connection point between the resistors 320a and 320b of the cell voltage dividing circuit 320, and the inverting input terminal is connected to the resistor 321a of the overcharge determination reference voltage circuit 321 and the reference power source 321b for overcharge determination. Each point is connected. The output terminal is connected to the input terminal of the microcomputer CPU3.

  The overdischarge determination reference voltage circuit 323 is a circuit that outputs an overdischarge voltage threshold for determining the presence or absence of an overdischarge state in the cell C32, for example, a reference voltage corresponding to a cell voltage of 3.0V. The overdischarge determination reference voltage circuit 323 includes a resistor 323a and an overdischarge determination reference power supply 323b. One end of the resistor 323a is connected to the positive terminal of the cell C32, the other end is connected to the positive terminal of the overdischarge determination reference power supply 323b, and the negative terminal of the overdischarge determination reference power supply 323b is connected to the negative terminal of the cell C32. Yes.

  The comparator 324 is an element that compares the voltage of the cell C32 divided by the cell voltage dividing circuit 320 with the reference voltage output from the overdischarge determination reference voltage circuit 323. The comparator 324 outputs a low level when the divided voltage of the cell C32 is smaller than the reference voltage corresponding to the overdischarge voltage threshold. The non-inverting input terminal of the comparator 324 is connected to the connection point between the resistors 320a and 320b of the cell voltage dividing circuit 320, and the inverting input terminal is connected to the resistor 323a of the overdischarge determination reference voltage circuit 323 and the overdischarge determination reference power supply 323b. Each point is connected. The output terminal is connected to the input terminal of the microcomputer CPU3.

  Here, the cell voltage voltage dividing circuit 310 of the overcharge / discharge detection circuit UL31 has a voltage division ratio equal to the voltage division ratio of the cell voltage voltage divider circuit 320 of the overcharge / discharge detection circuit UL32, and the combined resistance value is overcharged. It is set to be smaller than the combined resistance value of the cell voltage dividing circuit 320 of the discharge detection circuit UL32. The overcharge determination reference voltage circuit 311 of the overcharge / discharge detection circuit UL31 and the overcharge determination reference power supply circuit 321 of the overcharge / discharge detection circuit UL32 include the resistance values of the resistors 311a and 321a and the overcharge determination reference power supply. The internal resistance values of 311b and the overcharge determination reference power source 321b are set to be equal to each other. The overdischarge determination reference voltage circuit 313 of the overcharge / discharge detection circuit UL31 and the overdischarge determination reference power supply circuit 323 of the overcharge / discharge detection circuit UL32 include the resistance values of the resistors 313a and 323a and the reference power supply for overdischarge determination. The internal resistance values of 313b and overdischarge determination reference power supply 323b are set to be equal to each other. Further, the comparators 312 and 314 of the overcharge / discharge detection circuit UL31 and the comparators 322 and 324 of the overcharge / discharge detection circuit UL32 are set so that their input impedances are equal to each other. That is, the overcharge / discharge detection circuit UL31 is set so that the input impedance is smaller than that of the overcharge / discharge detection circuit UL32.

  Overcharge / discharge detection circuits UL33 to UL36 are connected to the cells C33 to C36, respectively. Since the overcharge / discharge detection circuits UL33 and UL35 are the same circuits as the overcharge / discharge detection circuit UL31, and the overcharge / discharge detection circuits UL34 and UL36 are the same circuits as the overcharge / discharge detection circuit UL32, the description thereof is omitted.

  The microcomputer CPU3 detects the overcharge and overdischarge states of the cells C31 to C36 based on the outputs of the overcharge / discharge detection circuits UL31 to UL36, and the cells C31 to C36 and the overcharge / discharge detection circuits UL31 to UL36, It is an element which detects the disconnection which generate | occur | produced between these by specifying a disconnection location. When at least one of the cells C31 to C36 is in an overcharged state or an overdischarged state, the microcomputer CPU3 outputs data relating to the cell in the overcharged state or the overdischarged state. Alternatively, when a disconnection occurs in at least one of the cells C31 to C36 and the overcharge detection circuits UL31 to UL36, data relating to the disconnection point is output. Twelve input terminals of the microcomputer CPU3 are connected to the comparators 312, 314, 322, 324, 332, 334, 342, 344, 352, 354, 362, 364 of the overcharge / discharge detection circuits UL31 to UL36, respectively. The output terminal is connected to the battery pack controller 12.

  Next, a specific operation will be described with reference to FIG. As shown in FIG. 6, for example, when the voltage of the cell C31 becomes larger than the overcharge voltage threshold value of 4.2V, the voltage of the cell C31 is divided by the cell voltage voltage dividing circuit 310 of the overcharge / discharge detection circuit UL31. Is done. The voltage of the cell C31 divided by the cell voltage dividing circuit 310 is compared with the reference voltage output from the overcharge determination reference voltage circuit 311 by the comparator 312. Since the voltage of the cell C31 is larger than the overcharge voltage threshold, the comparator 312 outputs a high level. When the output of the comparator 312 of the overcharge / discharge detection circuit UL31 becomes high level, the microcomputer CPU3 outputs data indicating that the cell C31 is in an overcharge state.

  Further, when the voltage of the cell C31 becomes smaller than the overdischarge voltage threshold value of 3.0 V, the voltage of the cell C31 is divided by the cell voltage voltage dividing circuit 310 of the overcharge / discharge detection circuit UL31. The voltage of the cell C31 divided by the cell voltage dividing circuit 310 is compared with the reference voltage output by the overdischarge determination reference voltage circuit 313 by the comparator 314. Since the voltage of the cell C31 is smaller than the overdischarge voltage threshold, the comparator 314 outputs a low level. When the output of the comparator 314 of the overcharge / discharge detection circuit UL31 becomes low level, the microcomputer CPU3 outputs data indicating that the cell C31 is in an overdischarge state.

  On the other hand, for example, when a disconnection occurs at a point C between the connection point of the cells C31 and C32 and the overcharge detection circuits UL31 and UL32, the total voltage of the cells C31 and C32 connected in series is Is applied to the overcharge / discharge detection circuits UL31 and UL32 connected in series.

  By the way, the input impedance of the overcharge / discharge detection circuit UL31 is set to be smaller than the input impedance of the overcharge / discharge detection circuit UL32. Therefore, a voltage smaller than the voltage of the cell C31 determined by the ratio of the input impedances of the overcharge / discharge detection circuits UL31 and UL32 is applied between the input terminals of the overcharge / discharge detection circuit UL31. A voltage higher than the voltage of the cell C32 determined by the ratio of the input impedances of the overcharge / discharge detection circuits UL31 and UL32 is applied between the input terminals of the overcharge / discharge detection circuit UL32. By optimally setting the input impedances of the overcharge / discharge detection circuits UL31 and UL32, the voltage between the input terminals of the overcharge / discharge detection circuit UL31 is set to a voltage smaller than the overdischarge voltage threshold, and the input terminal of the overcharge / discharge detection circuit UL32 The voltage in between can be greater than the overcharge voltage threshold.

  The voltage between the input terminals of the overcharge / discharge detection circuit UL31 is divided by the cell voltage dividing circuit 310. The voltage between the input terminals of the overcharge / discharge detection circuit UL31 divided by the cell voltage voltage divider circuit 310 is compared with the reference voltage output from the overdischarge determination reference voltage circuit 313 by the comparator 314. Since the voltage between the input terminals of the overcharge / discharge detection circuit UL31 is smaller than the overdischarge voltage threshold, the comparator 314 outputs a low level.

  The voltage between the input terminals of the overcharge / discharge detection circuit UL32 is divided by the cell voltage dividing circuit 320. The voltage between the input terminals of the overcharge / discharge detection circuit UL32 divided by the cell voltage divider circuit 320 is compared with the reference voltage output from the overcharge determination reference voltage circuit 321 by the comparator 322. Since the voltage between the input terminals of the overcharge / discharge detection circuit UL32 is larger than the overcharge voltage threshold, the comparator 322 outputs a high level.

  In the microcomputer CPU3, the comparator 314 of the overcharge / discharge detection circuit UL31 outputs a low level and the comparator 322 of the overcharge / discharge detection circuit UL32 outputs a high level, so that the connection point between the cells C31 and C32 and the overcharge / discharge detection circuit It is determined that a break has occurred at point C between UL 31 and UL 32, and data relating to the break location is output.

  Thereby, the disconnection which generate | occur | produced between the connection point of cell C31, C32 and the overcharge / discharge detection circuits UL31, UL32 can be identified and detected. Similarly, it is possible to detect and detect the disconnection occurring between the connection points of adjacent cells and the overcharge / discharge detection circuit corresponding to those cells among C32 to C36.

  Finally, specific effects will be described. According to the present embodiment, the charge state detection device CMU3 can identify the occurrence location of the disconnection between the cell and the overcharge / discharge detection circuit from the occurrence state of the overcharge state and the overdischarge state of the cell. Therefore, the reliability of the charge state detection device CMU3 and the charge state detection devices CMU1, CMU2, and CMU4 to CMUn having the same circuit configuration can be further improved.

  Further, in the vehicle, the charge state detection device CMU3 is provided between the cells C31 to C36 constituting the assembled battery 10 and the overcharge / discharge detection circuits UL31 to UL36 that detect the overcharge state and the overdischarge state of the cells C31 to C36. Can be detected. Therefore, the reliability of the charge state detection device CMU3 of the assembled battery 10 mounted on the vehicle and the charge state detection devices CMU1, CMU2, and CMU4 to CMUn having the same circuit configuration can be improved.

  In the above-described embodiment, in the overcharge / discharge detection circuit connected to the adjacent cell, the combined resistance value of the cell voltage divider circuit is set to a different value. It is not something that can be done. For example, as shown in FIG. 7, a resistor 315 is connected between the input terminals of the overcharge / discharge detection circuit UL31 separately from the cell voltage divider circuit 310, and the resistance value of this resistor is connected to an adjacent cell. A different value may be set for each charge / discharge detection circuit. In this case, in all the overcharge / discharge detection circuits, the cell voltage dividing circuit, the overcharge determination reference voltage circuit, the overdischarge determination reference voltage circuit, and the comparator can be shared, and the types of components constituting the circuit can be increased. Can be suppressed.

The block diagram of the assembled battery system using a charge condition detection apparatus is shown. The circuit diagram of the charge condition detection apparatus in 1st Embodiment is shown. The circuit diagram of another overcharge detection circuit is shown. The circuit diagram of the charge condition detection apparatus in 2nd Embodiment is shown. The circuit diagram of another overdischarge circuit is shown. The circuit diagram of the charge condition detection apparatus in 3rd Embodiment is shown. The circuit diagram of another overcharge / discharge detection circuit is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... assembled battery system, 10 ... assembled battery, CG1-CGn ... cell group, C11-C16, C21-C26, C31-C36 ... cell, CMU1-CMUn ... charge state detection apparatus (Battery charge state detection device), U11 to U16 ... Overcharge detection circuit (abnormality detection circuit), 110, 120 ... Cell voltage divider circuit, 110a, 110b, 120a, 120b ... Resistance, 111 121 ... Overcharge determination reference voltage circuit, 111a, 121a ... Resistance, 111b, 121b ... Overcharge determination reference power supply, 112, 122 ... Comparator, OR1 ... OR circuit (disconnection) Detecting circuit), 113... Resistor, L21 to L26... Overdischarge detecting circuit (abnormality detecting circuit), 210, 220... Cell voltage dividing circuit, 210a, 210b, 2 0a, 220b ... resistor, 211,221 ... overdischarge determination reference voltage circuit, 211a, 221a ... resistor, 211b, 221b ... overdischarge determination reference power supply, 212, 222 ... comparator , AND2 ... AND circuit (disconnection detection circuit), 213 ... resistor, UL31 to UL36 ... overcharge / discharge detection circuit (abnormality detection circuit), 310, 320 ... cell voltage divider circuit, 310a, 310b, 320a, 320b ... resistor, 311,321 ... overcharge determination reference voltage circuit, 311a, 321a ... resistor, 311b, 321b ... overcharge determination reference power supply, 313,323 ... Reference voltage circuit for overdischarge determination, 313a, 323a, resistor, 313b, 323b, reference power supply for overdischarge determination, 312, 314, 322, 324 Comparator, CPU3 ... microcomputer (disconnection detection circuit), 315 ... resistor, 11 ... current sensor, 12 ... assembled battery controller, 2 ... hybrid electric vehicle controller (HEV controller), 3 ... Inverters, 4 ... Motors

Claims (6)

In the assembled battery charge state detection device provided with an abnormality detection circuit that is connected to each of a plurality of cells connected in series constituting the assembled battery and detects an abnormality of the cell based on the voltage of the cell,
The abnormality detection circuit has a different input impedance for each adjacent cell connected, and further detects a disconnection between the cell and the abnormality detection circuit based on an output of the abnormality detection circuit. An assembled battery charge state detection device comprising a circuit.   2. The assembled battery charge state detection device according to claim 1, wherein the abnormality detection circuit has resistors having different resistance values between the input terminals connected to the cells for each of the adjacent cells to be connected. . The abnormality detection circuit detects the overcharge state of the cell by comparing the voltage of the cell with an overcharge voltage threshold,
The disconnection detection circuit determines that a disconnection has occurred between the cell and the abnormality detection circuit when the abnormality detection circuit detects an overcharge state of the cell. Or the assembled battery charge state detection apparatus of 2 description. The abnormality detection circuit detects an overdischarge state of the cell by comparing the voltage of the cell with an overdischarge voltage threshold,
The disconnection detection circuit determines that a disconnection has occurred between the cell and the abnormality detection circuit when the abnormality detection circuit detects an overdischarge state of the cell. The assembled battery charge state detection device according to 2. The abnormality detection circuit detects the overcharge state and the overdischarge state of the cell by comparing the voltage of the cell with an overcharge voltage threshold and an overdischarge voltage threshold;
The disconnection detection circuit, when one of the abnormality detection circuits connected to the adjacent cells detects the overcharge state of the cell and the other detects the overdischarge state of the cell, 3. The assembled battery charge state detection device according to claim 1, wherein it is determined that a disconnection has occurred between a connection point between cells and the abnormality detection circuit.   6. The assembled battery charge state detection device according to claim 1, wherein a state of charge of the assembled battery mounted on a vehicle is detected.

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