JP2015100199A - Disconnection detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disconnection detection device capable of detecting disconnection of a detection line connected to a terminal of a battery pack in a short time.SOLUTION: The disconnection detection device includes: detection lines 41, 42 and 43 connectable to connection points of neighboring battery cells 11a-11b and 11 and an end portion of a battery pack 10, respectively; a voltage detection circuit 50 for detecting a unit voltage between neighboring detection lines as a cell voltage of a corresponding battery cell; capacitors 21 and 23 connected between the detection line 41 that is connected to an upper terminal of the battery pack 10, and the detection line 43 different from the detection line 41; an inter-cell switch 31a of which both the ends are connected to a detection line 41a and a neighboring detection line 43b, respectively; a diode 32a that is connected in parallel with the inter-cell switch 31a for making a current flow; and a switch 35 for inversion connected between the detection line 41a and a detection line 42b. The inter-cell switch 31a is turned on for a predetermined period and then turned off. Thereafter, when the switch 35 is turned on, on the basis of a polarity of a most significant cell voltage, the disconnection of the detection line 41 is determined.

Description

  The present invention relates to a disconnection detection device for detecting disconnection of a detection line connected to an end of an assembled battery composed of a plurality of cell batteries.

  In recent years, an assembled battery in which a plurality of battery cells are connected in series to increase the voltage has been used. In such an assembled voltage, in order to protect each battery cell, the voltage of each battery cell included in the corresponding assembled battery is monitored by the monitoring IC. The monitoring IC includes a detection line connected to both electrodes of each battery cell, and detects the voltage of each battery cell from the voltage between adjacent detection lines.

  In the monitoring IC, when the detection line connected to the end of the assembled battery is disconnected, the voltage of the uppermost battery cell or the lowest battery cell of the assembled battery cannot be detected. Therefore, an abnormality detection device that detects disconnection of a detection line connected to an end of the assembled battery has been proposed.

  For example, the abnormality detection device disclosed in Patent Document 1 includes a disconnection of a detection line connected to the positive electrode of the uppermost battery cell and the negative electrode of the lowermost battery cell between the detection line and the adjacent detection line. This is detected because the polarity of the voltage is reversed from normal.

Japanese Patent No. 4766104

  Generally, a capacitor for noise removal or the like is externally attached between the abnormality detection device and the assembled battery. When the capacity of the external capacitor is large, it takes a long time to finish discharging the capacitor charge. As a result, even when the detection line connected to the end of the assembled battery is disconnected, it takes a long time until the polarity of the voltage is reversed and the disconnection can be detected. In particular, when power is supplied to the abnormality detection device from an external power source other than the assembled battery, the current consumed by flowing from the capacitor to the abnormality detection device is reduced, and it takes a long time to detect disconnection.

  In view of the above circumstances, it is a primary object of the present invention to provide a disconnection detection device capable of detecting disconnection of a detection line connected to an end of an assembled battery in a short time.

  In order to solve the above-described problem, the disconnection detection device according to claim 1 includes a connection point between adjacent battery cells and an end portion of the battery pack among a plurality of battery cells connected in series to each other included in the battery pack. A detection line that can be connected to each other, a voltage detection circuit that detects a unit voltage between the adjacent detection lines as a cell voltage of the corresponding battery cell, and an upper end of the assembled battery among the detection lines. A capacitor connected between the upper end line and the detection line different from the upper end line; and both ends of the capacitor connected to the upper end line and a detection line adjacent to the upper end line on the lower side; An inter-cell switch that short-circuits the adjacent detection lines, and an inversion switch connected between the uppermost line that is the uppermost detection line and the predetermined detection line so as to straddle the plurality of battery cells. And comprising the above After turning on the switch between the switches for a predetermined period and then turning it off, when the inversion switch is turned on, the top line of the upper end line is determined based on the polarity of the highest cell voltage detected by the voltage detection circuit. Determine disconnection.

  According to the first aspect of the present invention, when the upper end line is connected to the upper end portion of the assembled battery and each detection line is connected to the connection point of the battery cell, the unit voltage between the adjacent detection lines corresponds to the corresponding battery. It is detected as the cell voltage of the cell. Since the capacitor for noise removal is connected to the upper end line, even if the upper end line connected to the upper end of the assembled battery is disconnected, the polarity of the highest cell voltage is not used until the capacitor charge is discharged. Is the same as normal.

  Therefore, the inter-cell switch is turned on to short-circuit the upper end line and the adjacent detection line. As a result, the electric charge is rapidly discharged from the capacitor. By turning on the inter-cell switch for a predetermined period, the electric charge is discharged until the highest cell voltage becomes close to 0V. After the inter-cell switch is turned off, the inversion switch connected between the uppermost detection line and the predetermined detection line is turned on so as to straddle the plurality of battery cells. As a result, the detected voltage of the uppermost battery cell has a polarity opposite to the polarity of the battery cell, so that the disconnection of the upper end line can be determined based on the polarity of the uppermost cell voltage. Therefore, by rapidly discharging the capacitor charge, the disconnection of the detection line connected to the upper end of the assembled battery can be detected in a short time.

  When the uppermost detection line is connected to the upper end portion of the assembled battery, the upper end line and the uppermost line are the same detection line.

  The disconnection detecting device according to claim 2 is connectable to a connection point of the adjacent battery cells and an end portion of the assembled battery among a plurality of battery cells connected in series to each other included in the assembled battery. A detection line; a voltage detection circuit that detects a unit voltage between the adjacent detection lines as a cell voltage of the corresponding battery cell; and a lower end line connected to a lower end of the assembled battery among the detection lines; A capacitor connected between the detection line different from the lower end line, and both ends connected to the detection line adjacent to the lower end line on the lower end line and the upper side, respectively, and the adjacent detection to the lower end line An inter-cell switch that short-circuits the line, and an inversion switch that is connected between the lowest detection line that is the lowest detection line and the predetermined detection line so as to straddle the plurality of battery cells. , The inter-cell switch When the inversion switch is turned on after being turned on after being turned on for a predetermined period, the disconnection of the lower end line is determined based on the polarity of the lowest cell voltage detected by the voltage detection circuit. .

  According to the invention described in claim 2, when the lower end line is connected to the lower end portion of the assembled battery and each detection line is connected to the connection point of the battery cell, the unit voltage between the adjacent detection lines corresponds to the corresponding battery. It is detected as the cell voltage of the cell. Since the capacitor for noise removal is connected to the lower end line, even if the lower end line connected to the lower end part of the battery pack is disconnected, the polarity of the lowest cell voltage is required until the capacitor charge is discharged. Is the same as normal.

  Therefore, the inter-cell switch is turned on to short-circuit the lower end line and the adjacent detection line. As a result, the electric charge is rapidly discharged from the capacitor. By turning on the inter-cell switch for a predetermined period, the electric charge is discharged until the lowest cell voltage becomes close to 0V. After the inter-cell switch is turned off, the inversion switch connected between the lowest detection line and the predetermined detection line is turned on so as to straddle the plurality of battery cells. Thereby, the voltage of the lowest battery cell detected can determine the disconnection of the lower end line based on the voltage polarity of the lowest battery cell. Therefore, the discharge of the detection line connected to the lower end of the assembled battery can be detected in a short time by rapidly discharging the capacitor.

  In addition, when connecting the lowest detection line to the lower end part of an assembled battery, a lower end line and the lowest line become the same detection line.

The figure which shows the structure of the disconnection detection apparatus which concerns on 1st Embodiment. The figure which shows the process of determining the disconnection of the detection line connected to the upper end part of an assembled battery. The time chart which shows the change of a cell voltage. The figure which shows the process in which the disconnection of the detection line connected to the lower end part of an assembled battery is determined. The figure which shows the structure of the disconnection detection apparatus which concerns on 2nd Embodiment. FIG. The figure which shows the structure of the disconnection detection apparatus which concerns on 3rd Embodiment. The figure which shows the structure of the disconnection detection apparatus which concerns on other embodiment. The figure which shows the structure of the disconnection detection apparatus which concerns on other embodiment. The figure which shows the structure of the disconnection detection apparatus which concerns on other embodiment.

  Hereinafter, each embodiment in which the disconnection detection device is applied to a hybrid vehicle will be described with reference to the drawings. The hybrid vehicle includes a main battery that supplies electric power to the motor and an auxiliary battery that supplies electric power to the electrical components of the vehicle. In the following embodiments, portions that are the same or equivalent to each other are denoted by the same reference numerals in the drawings, and the description of the portions with the same reference numerals is incorporated.

(First embodiment)
In FIG. 1, the block diagram of the disconnection detection apparatus based on this embodiment is shown. The disconnection detection device 40 according to the present embodiment operates by receiving power from an external power source 60 (auxiliary battery) and detects the state of the assembled battery 10 (main device battery). The assembled battery 10 is, for example, a lithium ion storage battery configured by connecting a plurality of battery cells 11 a to 11 b and 11 in series. In the present embodiment, the assembled battery 10 is composed of five battery cells 11a-b, 11 including the uppermost battery cell 11a and the lowermost battery cell 11b. The number of cells may be increased or decreased.

  The disconnection detection device 40 includes a voltage detection circuit 50, other circuits 52, detection lines 41, 42, 43, diodes 32a-b, 33, inter-cell switches 31a-b, 31, an inversion switch 35, an RC filter circuit 20, and a bypass. A capacitor 23 is provided.

  The detection lines 41, 42, and 43 are electric wires that can be connected to the connection points of adjacent battery cells and the ends of the assembled battery 10, respectively. In the present embodiment, the detection line 41 (upper end line, uppermost line) is the uppermost detection line, and is connected to the upper end portion of the assembled battery 10, that is, the positive electrode of the battery cell 11a and the voltage detection circuit 50. . The detection line 42 (lower end line, lowest line) is the lowest detection line, and is connected to the lower end of the assembled battery 10, that is, the negative electrode of the battery cell 11b and the voltage detection circuit 50. The detection lines 43 are connected to the connection point of the battery cell 11 and the voltage detection circuit 50, respectively. Each of the detection lines 41, 42, and 43 includes a connector C, and includes a harness or the like on the assembled battery 10 side with respect to the connector C and wiring on the voltage detection circuit 50 side with respect to the connector C. The disconnection of the detection lines 41 and 42 mainly assumes disconnection of a harness or the like closer to the assembled battery 10 than the connector C.

  The detection lines 41, 42, and 43 branch to the detection lines 41a and 41b, 42a and 42b, and 43a and 43b on the voltage detection circuit 50 side of the connector C via the resistors 22a and 22b, respectively. The circuit 50 is connected. The resistor 22b connected to the lower detection line of the adjacent detection lines and the resistor 22a connected to the upper detection line are connected in series via the capacitor 21. The resistors 22a and 22b and the capacitor 21 constitute an RC filter circuit 20 for removing noise. Further, both ends of the bypass capacitor 23 are connected to the uppermost detection line 41b and the lowermost detection line 42a, respectively. Further, the switch 24 is connected between the detection line 41b and the detection line 42a. The switch 24 is a switch corresponding to high voltage and low current, and is composed of, for example, an n-type MOSFET and an internal resistance. When the cell voltage is not detected, the switch 24 is turned on to discharge the capacitor 21 and the bypass capacitor 23.

  The inter-cell switch 31 is a switch in which both ends are connected to an upper detection line 43a and a lower detection line 43b among adjacent detection lines, and the detection line 43a and the adjacent detection line 43b are short-circuited. The uppermost inter-cell switch 31a is a switch whose both ends are connected to the detection line 41a and a detection line 43b adjacent to the detection line 41a on the lower side, and short-circuits the detection line 41a and the adjacent detection line 43b. The lowest inter-cell switch 31b is a switch that is connected at both ends to the detection line 42b and the detection line 43a adjacent to the detection line 42b on the upper side, and short-circuits the detection line 42b and the adjacent detection line 43a.

  The inter-cell switches 31a-b, 31 are equalization switches used for equalizing the battery cells 11a-b, 11. A battery cell that needs to be discharged is selected according to the remaining capacity, and an inter-cell switch corresponding to the selected battery cell is turned on. Thereby, the selected battery cell is discharged and the battery cells 11a to 11b and 11 are equalized. The inter-cell switches 31a to 31b, 31 are switches corresponding to a low voltage and a high current, and are composed of, for example, a p-type MOSFET. The diodes 32a to 32b (one-way conduction element) and the capacitor 21 are connected in parallel to the inter-cell switches 31a to 31b and 31, respectively.

  The diodes 32a to 32b have anodes connected to the lower detection lines 42b and 43b, cathodes connected to the upper detection lines 41a and 43a, and currents flow from the lower detection lines to the upper detection lines. It is an element that flows. The diode 33 is a unidirectional conducting element connected to two detection lines 42a and 42b and 43a and 43b branched through resistors 22a and 22b. The anode of the diode 33 is connected to the cathode of the lower diode 32, and the cathode of the diode 33 is connected to the anode of the upper diode 32. The voltage applied between the detection lines is limited by the diodes 32a to 32b, 32, and 33, and the voltage detection circuit 50, the other circuit 52, and the like are protected.

  The inversion switch 35 is a switch having both ends connected to the uppermost detection line 41a and the lowermost detection line 42b. The inversion switch 35 is a switch corresponding to a high voltage and low current, and is composed of, for example, a p-type MOSFET and an internal resistance.

  The voltage detection circuit 50 includes a multiplexer 51 that is a selection switch group, and detects a unit voltage between adjacent detection lines as a cell voltage of the corresponding battery cell 11. Specifically, two adjacent detection lines are selected by the multiplexer 51, and a unit voltage between the selected two detection lines is detected as a cell voltage of the corresponding battery cells 11a to 11b. The multiplexer 51 selects one of 42b and 43b as the negative detection line, and selects one of 41a and 43a as the positive detection line. Here, the interval between the detection lines connected to different parts of the assembled battery is referred to as a detection line interval.

  The other circuit 52 is, for example, an overcharge detection circuit that detects overcharge based on the cell voltage detected by the voltage detection circuit 50, or a discharge detection circuit that detects overdischarge.

  Voltage detection circuit 50, other circuit 52, diodes 32a-b, 32, 33, inter-cell switches 31a-b, 31, inversion switch 35, switch 24, detection lines 41a- b, 42a-b, 43a-b are mounted on the semiconductor substrate 30.

  Next, a method for determining the disconnection of the detection line 41 connected to the upper end portion of the assembled battery 10 will be described with reference to FIGS. 2 and 3. FIG. 2 is a diagram illustrating a process of determining disconnection of the detection line 41. FIG. 2A is a diagram showing a current flow when the inter-cell switch 31a is turned on, and FIG. 2B is a diagram showing a current flow when the inversion switch 35 is turned on. is there. FIG. 3 is a time chart showing the on / off state of the inter-cell switch 31a, the on / off state of the inversion switch 35, and the change in the highest cell voltage.

  First, at time t1, the highest inter-cell switch 31a corresponding to the highest battery cell 11a is turned on. As a result, the detection line 43b adjacent to the detection line 41a is short-circuited, and charges are rapidly transferred from the capacitor 21 and the bypass capacitor 23 connected in parallel to the inter-cell switch 31a along the path indicated by the arrow in FIG. Discharged. After the inter-cell switch 31a is turned on for the period T (predetermined period), the inter-cell switch 31a is turned off at time t2. In the period T, the uppermost cell voltage rapidly decreases from the voltage V to near 0 V as the electric charges are discharged from the capacitor 21 and the bypass capacitor 23. The period T is set according to the capacity of the capacitor 21 and the bypass capacitor 23.

  Next, the inversion switch 35 is turned on at time t3 and turned off at time t4. When the detection line 41 is disconnected, when the inversion switch 35 is turned on, the diode 32a is turned on, and a current flows through a path indicated by an arrow in FIG. Specifically, a current flows from the negative electrode of the battery cell 11a, that is, the positive electrode of the battery cell 11 adjacent to the battery cell 11a, to the inverting switch 35 through the resistor 22b, the detection line 43b, the diode 32a, and the detection line 41a. Assuming that the polarity of the normal cell voltage is positive and the voltage drop of the diode 32a is Vf, the highest cell voltage converges to -Vf by turning on the inversion switch 35.

  On the other hand, when the detection line 41 is not disconnected, when the inter-cell switch 31a is turned off, a current flows to the capacitor 21 connected in parallel to the inter-cell switch 31a. Even after the inversion switch 35 is turned on, current continues to flow to the capacitor 21 connected in parallel to the inter-cell switch 31a until the highest cell voltage converges. Thus, after the inter-cell switch 31a is turned off, the uppermost cell voltage converges to a positive voltage obtained by subtracting the voltage drop of the resistors 22a and 22b from the voltage V.

  Therefore, when the inversion switch 35 is turned on, the disconnection of the detection line 41 can be determined based on whether or not the polarity of the highest cell voltage is inverted. The determination of the disconnection of the detection line 41 may be performed after time t3.

  Next, a method for detecting disconnection of the detection line 42 connected to the lower end of the assembled battery 10 will be described with reference to FIG. 4A is a diagram showing a current flow when the inter-cell switch 31b is turned on, and FIG. 4B is a diagram showing a current flow when the inverting switch 35 is turned on. is there. The time chart showing the on / off state of the inter-cell switch 31b, the on / off state of the inversion switch 35, and the change in the lowest cell voltage is the same as that in FIG.

  First, at time t1, the lowest inter-cell switch 31b corresponding to the lowest battery cell 11b is turned on. As a result, the detection line 43a adjacent to the detection line 42b is short-circuited, and the charge is rapidly discharged from the capacitor 21 connected in parallel to the inter-cell switch 31b through the path indicated by the arrow in FIG. After the inter-cell switch 31b is turned on for the period T (predetermined period), the inter-cell switch 31b is turned off at time t2. In the period T, the lowest cell voltage rapidly decreases to near 0V.

  Next, the inversion switch 35 is turned on at time t3 and turned off at time t4. When the detection line 42 is disconnected, when the inversion switch 35 is turned on, the diode 32b is turned on, and a current flows through a path indicated by an arrow in FIG. Specifically, a current flows from the positive electrode of the battery cell 11a to the diode 32b via the inversion switch 35 and the detection line 42b, and the lowest cell voltage converges to -Vf. On the other hand, when the detection line 42 is not disconnected, the lowest cell voltage converges to a positive voltage after the inter-cell switch 31b is turned off.

  Therefore, when the inversion switch 35 is turned on, the disconnection of the detection line 42 can be determined based on whether or not the polarity of the lowest cell voltage is inverted. The disconnection of the detection line 42 may be determined after the time t3.

  Although the method for determining the disconnection of the detection line 41 and the method for determining the disconnection of the detection line 42 have been described, the disconnection of the detection line 41 and the detection line 42 may be determined simultaneously. Specifically, the inter-cell switch 31a and the inter-cell switch 31b are simultaneously turned on for a predetermined period and then turned off, and then the inversion switch 35 is turned on. When the inversion switch 35 is turned on, the disconnection of the detection line 41 and the detection line 42 is determined based on the polarities of the highest cell voltage and the lowest cell voltage.

  According to 1st Embodiment described above, there exist the following effects.

  The detection lines 41 and 42 connected to the upper end and the lower end of the assembled battery 10 in a short time by turning on the inter-cell switches 31a and 31b and rapidly discharging the capacitor 21 and the bypass capacitor 23. Disconnection can be detected.

  A low withstand voltage high current switch can be adopted as the inter-cell switches 31a and 31b, and a high withstand voltage low current switch can be adopted as the inversion switch 35. Therefore, the cost and the switch mounting area on the semiconductor substrate 30 can be suppressed as compared with the case where a high withstand voltage high current switch is used.

(Modification of the first embodiment)
The inter-cell switches 31a to 31b and 31 do not have to be used as equalization switches. In this case, at least the inter-cell switch 31a and the inter-cell switch 31b may be installed.

  The diodes 32a to 32b, 32, and 33 do not have to serve as protection diodes. The diodes 32a to 32b may be parasitic diodes of the inter-cell switches 31a to 31b and 31. Further, at least the diode 32a and the diode 32b may be installed. The diode 33 may not be installed.

(Second Embodiment)
Next, the disconnection detection device 40 according to the second embodiment will be described with reference to FIG. 5 for differences from the first embodiment. In the second embodiment, the assembled battery 10 is composed of four battery cells. Since the number of battery cells is smaller than the number between the detection lines, the uppermost detection line 41 (uppermost line) is not connected to the assembled battery 10, and is the second detection line 43 ′ (upper end line) from the top. ) Is connected to the upper end of the battery pack 10. The detection lines 42, 43, 43 ′ are composed of a harness or the like closer to the assembled battery 10 than the connector C, and wiring connected to the voltage detection circuit 50. On the other hand, the detection lines 41a and 41b are composed of wiring connected to the voltage detection circuit 50 rather than the connector C.

  Next, a method for determining disconnection of the detection line 43 ′ connected to the upper end portion of the assembled battery 10 in the present embodiment will be described. First, the inter-cell switch 31 ′ having both ends connected to the detection line 43 a ′ and the detection line 43 b adjacent to the detection line 43 a ′ on the lower side is turned on. The inter-cell switch 31 'is an inter-cell switch corresponding to the uppermost battery cell 11' in the present embodiment. When the inter-cell switch 31 ′ is turned on, electric charges are rapidly discharged from the capacitor 21 connected in parallel to the inter-cell switch 31 ′, the upper capacitor 21, and the bypass capacitor 23.

  The inter-cell switch 31 ′ is turned on for a predetermined period, the uppermost cell voltage is made close to 0 V, and then the inter-cell switch 31 ′ is turned off. Thereafter, when the inversion switch 35 is turned on, when the detection line 43 ′ is disconnected, the diode 32 ′ connected in parallel to the inter-cell switch 31 ′, the diode 33 connected to the upper side of the diode 32 ′, and The diode 32a is turned on, and a current flows through a path indicated by an arrow in FIG. Specifically, a current flows from the positive electrode of the battery cell 11 adjacent to the battery cell 11 ′ to the resistor 22 b and the diode 32 ′. Then, a current flows from the detection line 43 a ′ to the detection line 41 a through the diode 33 and the diode 32 a, and a current flows to the inversion switch 35. As a result, the highest cell voltage converges to -Vf. On the other hand, if the detection line 43 'is not disconnected, the highest cell voltage converges to a positive voltage after the inter-cell switch 31' is turned off. Therefore, when the inversion switch 35 is turned on, the disconnection of the detection line 43 'can be determined based on whether or not the polarity of the highest cell voltage is inverted.

  Similarly, even when the lowest detection line 42 is not connected to the assembled battery 10, the disconnection of the detection line 43 connected to the lower end portion of the assembled battery 10 can be determined. For example, when the lowest detection line 42 (lowest line) is not connected to the assembled battery 10 and the second detection line 43 (lower end line) from the bottom is connected to the lower end of the assembled battery 10, it is for reversal. A current flows from the switch 35 through the detection line 42b, the diode 32b, the diode 33 connected to the upper side of the diode 32b, and the diode 32. As a result, the lowest cell voltage converges to -Vf.

  According to 2nd Embodiment described above, there exist the following effects.

  Even when all the detection lines connected to the voltage detection circuit 50 are not used, the disconnection of the detection lines connected to the end of the assembled battery 10 can be detected in a short time.

  By connecting both ends of the inversion switch 35 to the uppermost detection line 41a and the lowermost detection line 42b, the connection of the inversion switch 35 is performed regardless of how the detection line and the assembled battery 10 are connected. There is no need to change.

  Inter-cell switches 31a, 31 ′, 31, 31b are connected to all the detection lines, and diodes 32a, 32 ′, 32, 32 are connected in parallel to the inter-cell switches 31a, 31 ′, 31, 31b. 32b are connected to each other. Therefore, regardless of how the detection line and the assembled battery 10 are connected, the highest and lowest cell voltages can be reduced to near 0 V and the polarity can be reversed in a short time. Therefore, the disconnection of the detection line connected to the upper end portion of the assembled battery 10 and the detection line connected to the lower end portion of the assembled battery 10 can be detected regardless of how the detection line and the assembled battery 10 are connected.

  ・ By forming the current path from the top line to the top line and the current path from the bottom line to the bottom line with diodes, the time until the polarity of the cell voltage, which has dropped to near 0V, is reversed is shortened. can do.

(Modification of the second embodiment)
The diodes 32a and 32 connected in parallel to the inter-cell switches 31a and 31 and the inter-cell switches 31a and 31 are at least between the detection lines between the uppermost detection line 41a and the adjacent detection line 43b ′, and What is necessary is just to be connected between the predetermined number of detection lines adjacent between detection lines. In this way, even when the predetermined number of upper detection lines are not used for battery cell voltage detection, disconnection of the detection lines connected to the upper end of the battery pack 10 can be detected. When the upper end line and the uppermost line are the same detection line, the predetermined number may be zero. That is, only the inter-cell switch 31a and the diode 32a may be used.

  The diodes 32b and 32 connected in parallel to the inter-cell switches 31b and 31 and the inter-cell switches 31b and 31 are at least between the detection lines between the lowest detection line 42b and the adjacent detection line 43a and the detection thereof. What is necessary is just to be connected between the predetermined number of detection lines adjacent between lines. In this way, even when a predetermined number of lower detection lines are not used for voltage detection of the battery cell, it is possible to determine disconnection of the detection lines connected to the lower end of the battery pack 10. When the lower end line and the lowest line are the same detection line, the predetermined number may be zero. That is, only the inter-cell switch 31b and the diode 32b may be used.

  -The diode 33 does not need to be installed. Although the time until the polarity of the cell voltage is reversed is longer than when the diode 33 is installed, a current path passing through the resistors 22a and 22b is formed without installing the diode 33.

(Third embodiment)
Next, the disconnection detection device 40 according to the third embodiment will be described with reference to FIG. 6 and different points from the first embodiment. The disconnection detection apparatus 40 according to the third embodiment includes an inter-cell switch 31a and an inter-cell switch 31b that are different from the equalization switch, and does not include the diodes 32a to 32b, 32, and 33. The inter-cell switch 31a and the inter-cell switch 31b are switches corresponding to high voltage and high current.

  Next, in the present embodiment, a method for determining disconnection of the detection line 41 connected to the upper end portion of the assembled battery 10 will be described. First, the inter-cell switch 31a is turned on for a predetermined period to make the highest cell voltage close to 0V, and then the inter-cell switch 31a is turned off. Thereafter, when the inversion switch 35 is turned on, when the detection line 41 is disconnected, the potential of the detection line 41a becomes equal to the potential of the lower end of the inversion switch 35, that is, the potential of the detection line 42. Therefore, the highest cell voltage has a negative polarity and converges to the voltage of the four battery cells 11 and 11b excluding the highest battery cell 11a. Therefore, when the inversion switch 35 is turned on, the disconnection of the detection line 41 can be determined based on whether or not the polarity of the highest cell voltage is inverted. The presence or absence of polarity inversion can be determined even during the convergence of the highest cell voltage, so that the disconnection of the detection line 41 can be detected in a short time.

  Next, a method for determining disconnection of the detection line 42 connected to the lower end of the assembled battery 10 will be described. First, the inter-cell switch 31b is turned on for a predetermined period, the lowest cell voltage is made close to 0V, and then the inter-cell switch 31b is turned off. Thereafter, when the inversion switch 35 is turned on, when the detection line 42 is disconnected, the potential of the detection line 42b becomes equal to the potential of the upper end of the inversion switch 35, that is, the potential of the detection line 41. Therefore, the lowest cell voltage has a negative polarity and converges to the voltage of four battery cells 11a and 11 minutes excluding the lowest battery cell 11b. Therefore, when the inversion switch 35 is turned on, the disconnection of the detection line 42 can be determined based on whether or not the polarity of the lowest cell voltage is inverted. The presence or absence of polarity reversal can be determined even while the lowest cell voltage converges, so that the disconnection of the detection line 42 can be detected in a short time.

  In the present embodiment, the disconnection cannot be detected when the detection line 41 and the detection line 42 are disconnected simultaneously, but the disconnection can be detected when one of the detection line 41 and the detection line 42 is disconnected.

  According to 3rd Embodiment described above, there exist the following effects.

  The disconnection of the detection lines 41 and 42 connected to the upper end and the lower end of the assembled battery 10 can be determined based on the polarities of the highest and lowest cell voltages. Moreover, since the polarity of the highest and lowest cell voltages can be determined even while the cell voltage converges, the disconnection of the detection lines 41 and 42 connected to the upper end portion or the lower end portion of the assembled battery 10 in a short time, respectively. It can be detected.

(Modification of the third embodiment)
As shown in FIG. 5, the uppermost detection line 41 may not be connected to the assembled battery 10. Even in such a case, at least if there is an inter-cell switch 31 ′ having both ends connected to the upper end line connected to the upper end portion of the assembled battery 10 and the detection line adjacent to the upper end line on the lower side, the same applies. The disconnection of the upper end line can be detected. Specifically, when the inversion switch 35 is turned on, if the upper end line is disconnected, the upper end line potential becomes equal to the detection line 42 potential, and the uppermost cell voltage converges to a negative voltage.

  In addition, the lowest detection line 42 may not be connected to the assembled battery 10. Even in such a case, if there is an inter-cell switch 31 having both ends connected to the lower end line connected to the lower end portion of the assembled battery 10 and the detection line adjacent to the lower end line on the upper side, similarly, The disconnection of the lower end line can be detected. Specifically, when the inversion switch 35 is turned on, when the lower end line is broken, the potential of the lower end line becomes equal to the potential of the detection line 41, and the lowest cell voltage converges to a negative voltage.

(Other embodiments)
The inversion switch 35 does not have to straddle all the battery cells. As shown in FIG. 7, it may be composed of a reversing switch 35a and a reversing switch 35b. The reversing switch 35a is connected to the detection line 41a and the detection line 43a so as to straddle at least two battery cells. The reversing switch 35b is connected to the detection line 42b and the detection line 43a so as to straddle at least two battery cells. When determining the disconnection of the detection line 41, the inversion switch 35a is turned on, and when determining the disconnection of the detection line 42, the inversion switch 35b is turned on. As the inversion switches 35a and 35b, switches having a lower withstand voltage than the inversion switch 35 can be used.

  As shown in FIG. 8, the inversion switch 35 may be composed of a plurality of inversion switches 35c and 35d (partial inversion switches) connected in series. The reversing switches 35c and 35d straddle at least two detection lines. In this case, the battery cell to which the detection line that is the subject of the disconnection determination is connected to the electrode and the reversing switch that straddles the battery cell adjacent to the battery cell are turned on. When the disconnection of the detection line 41 is determined, the reversing switch 35c straddling the battery cell 11a and the second battery cell 11 from the top is turned on. When determining the disconnection of the detection line 42, the reversing switch 35d straddling the battery cell 11b and the second battery cell 11 from the bottom is turned on. Thereby, it is possible to determine the disconnection by turning on only the inversion switch corresponding to the detection line that is the target of the disconnection determination. Further, as the inverting switches 35c and 35d, switches having a lower withstand voltage than the inverting switch 35 can be used.

  As shown in FIG. 9, the inversion switch 35 may be connected anywhere as long as it is electrically connected to the uppermost detection line 41 and the lowermost detection line 42. In FIG. 9, the capacitor 21 and the like are omitted.

  -The structure which is provided with the switch 31a between cells and can detect only the disconnection of the detection line 41 connected to the upper end part of the assembled battery 10 may be sufficient. Moreover, the structure provided with the switch 31b between cells and detecting only the disconnection of the detection line 42 connected to the lower end part of the assembled battery 10 may be sufficient.

  The detection lines 41, 42, and 43 may not be branched through the resistors 22a and 22b. That is, the detection lines 41a and 41b, 42a and 42b, and 43a and 43b may be one detection line 41, 42, and 43.

  -You may make it supply electric power from the assembled battery 10 to the disconnection detection apparatus 40. FIG.

  DESCRIPTION OF SYMBOLS 10 ... Battery assembly, 11a, 11b, 11, 11 '... Battery cell, 21 ... Capacitor, 31a, 31b, 31, 31' ... Inter-cell switch, 32a, 32b, 32, 32 '... Diode, 35, 35a-d ... reversing switches, 41a-b, 42a-b, 43a-b, 43'a-b ... detection lines.

Claims (7)

Connectable to the connection point of the adjacent battery cells and the end of the assembled battery among the plurality of battery cells (11a-b, 11, 11 ') connected in series to each other included in the assembled battery (10) Detection lines (41, 42, 43, 43 ');
A voltage detection circuit (50) for detecting a unit voltage between adjacent detection lines as a cell voltage of the corresponding battery cell;
A capacitor (21) connected between an upper end line (41, 43 ′) connected to an upper end portion of the assembled battery among the detection lines, and the detection line different from the upper end line;
An inter-cell switch (31a, 31 ′) for connecting both ends to the detection line adjacent to the upper end line on the upper end line and the lower side, and short-circuiting the upper end line and the adjacent detection line;
A reversing switch (35, 35a, 35c) connected between the uppermost detection line and the predetermined detection line so as to straddle the plurality of battery cells;
Based on the polarity of the highest cell voltage detected by the voltage detection circuit when the inversion switch is turned on after the inter-cell switch is turned on after being turned on for a predetermined period, the upper end line A disconnection detecting device characterized by determining disconnection of a wire. Connectable to the connection point of the adjacent battery cells and the end of the assembled battery among the plurality of battery cells (11a-b, 11, 11 ') connected in series to each other included in the assembled battery (10) Detection lines (41, 42, 43, 43 ');
A voltage detection circuit (50) for detecting a unit voltage between adjacent detection lines as a cell voltage of the corresponding battery cell;
A capacitor (21) connected between the lower end line (42) connected to the lower end of the assembled battery among the detection lines and the detection line different from the lower end line;
An inter-cell switch (31b) for connecting both ends to the detection line adjacent to the lower end line on the lower end line and the upper side, and short-circuiting the lower end line and the adjacent detection line;
A reversing switch (35, 35b, 35d) connected between the lowest detection line which is the lowest detection line and the predetermined detection line so as to straddle a plurality of the battery cells,
The lower end line is turned on based on the polarity of the lowest cell voltage detected by the voltage detection circuit when the inversion switch is turned on after the inter-cell switch is turned on after being turned on for a predetermined period. A disconnection detecting device characterized by determining disconnection of a wire. The inter-cell switch (31a, 31) is provided between the detection line between the uppermost line and the detection line adjacent to the uppermost line and between a predetermined number of detection lines adjacent between the detection lines. Installed,
The disconnection according to claim 1, wherein a unidirectional conducting element (32a, 32) and a capacitor (21) for passing a current from the lower detection line to the upper detection line are connected in parallel with each inter-cell switch. Detection device. The inter-cell switches (31b, 31) are respectively connected between detection lines between the lowest line and the detection line adjacent to the lowest line, and between a predetermined number of detection lines adjacent between the detection lines. Installed,
The disconnection according to claim 2, wherein a unidirectional conducting element (32b, 32) and a capacitor (21) for passing a current from the lower detection line to the upper detection line are connected in parallel with each inter-cell switch. Detection device.   5. The disconnection detection according to claim 1, wherein both ends of the reversing switch are connected to the uppermost line as the uppermost detection line and the lowermost line as the lowermost detection line, respectively. apparatus. The inter-cell switch is installed for each detection line between the adjacent detection lines,
The disconnection detecting device according to claim 5, wherein a unidirectional conducting element and a capacitor (21) for passing a current from the lower detection line to the upper detection line are connected in parallel with each inter-cell switch. The inversion switch is composed of a plurality of partial inversion switches (35c, 35d) connected in series,
Among the plurality of partial reversing switches, as the reversing switch, the battery cell to which the detection line, which is the subject of disconnection determination, is connected to an electrode, and the partial reversal straddling the battery cell adjacent to the battery cell. The disconnection detection device according to claim 6, wherein the switch is turned on.

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