JP2001025173A - Set-battery fault determination apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To alleviate the supervising load of a fault determining means to simplify the structure by supervising voltage change of each cell group with a voltage output means in cell group units, and then determining generation of a fault condition. SOLUTION: Unit cells 11, consisting of a lithium secondary batteries, are connected in series to form a cell group 12, and by having these cell groups 12 connected in series a set battery is formed, and thereby a fault detecting apparatus 13 is allocated between the cell group 12 and a voltage detector. When a fault condition of the unit cell 11 forming the cell group 12 is detected with a lower limit voltage detecting circuit 30, an upper limit voltage detecting circuit 31 and an excess rising temperature detecting circuit 37 forming a fault detecting apparatus 13, an AND gate 29 changes the terminal voltage of the cell group 12 with a switch 38. Thereby, the CPU can determine generation of a fault in the unit cell within the cell group 12, by only connecting the fault detecting apparatus 13 and the voltage detector of a control unit with the voltage detecting lines W+, W-.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery pack comprising a plurality of cell groups formed by connecting a plurality of unit cells each comprising a secondary battery in series and the occurrence of abnormalities during charging and discharging. The present invention relates to an abnormality determination device for determining the abnormality and an abnormality determination method for the assembled battery.

[0002]

2. Description of the Related Art In recent years, a hybrid electric vehicle (hereinafter, referred to as a hybrid vehicle) combining a mechanism of an electric vehicle and a gasoline engine has been developed in order to achieve both low pollution and high running performance.
HEV) has been developed. Since an HEV is equipped with a gasoline engine, it can maintain the same running performance as a gasoline-powered vehicle without using a large-capacity battery as an electric vehicle, but has low engine efficiency and emits carbon dioxide and nitrogen oxides. When the motor rotates at a low rotation speed, the motor is driven by the battery, so that low pollution can be achieved.

[0003] Even in such an HEV, electric power supplied from a battery is used at the time of starting or at the time of full acceleration.
High output is required for batteries. Also, HEV is
Since many components such as an engine, a motor / generator, and a battery must be mounted, and the weight of the entire vehicle increases, the battery must be as high in performance and light as an electric vehicle. Have been.

[0004] Under such circumstances, lithium batteries have attracted attention as an alternative to lead, nickel cadmium, nickel hydride batteries and the like. Lithium batteries have a weight energy density that is about three to four times higher than lead or nickel cadmium batteries of the same capacity, and are expected to be applied as suitable for HEVs that require small size and light weight. I have.

However, lithium batteries are susceptible to overcharging and overdischarging, and if not used within a specified voltage range, the materials may decompose and the capacity may be significantly reduced, or the battery may become unusable due to abnormal heat generation. There is. Therefore, when using a lithium battery, the upper limit voltage and the lower limit voltage are clearly specified, and charge / discharge control is performed so that the terminal voltage is within the range, or a protection circuit that limits the voltage range is used as a set. It is common to use.

[0006] Incidentally, batteries used in electric vehicles and HEVs require a high voltage to drive a motor, and therefore are usually constituted by connecting a plurality of unit cells in series. For example, to obtain a battery voltage of 300 V, about 150 cells are connected in series for a 2 V lead battery per unit cell, and about 80 cells are connected in series for a 3.6 V lithium battery per unit cell. Become.

In the case of charging a battery pack formed by connecting a number of unit cells in series as described above, charging has conventionally been controlled by monitoring the voltage between the positive and negative terminals of the battery pack. For example, the voltage range per unit cell is 1.8-2.
In the case of 150 lead batteries connected in series at 4 V, charge / discharge control was performed so that the voltage range of the assembled battery would be in the range of 270 to 360 V.

In this case, a problem is a variation in terminal voltage between the unit cells based on a state of charge (hereinafter, referred to as SOC) of each unit cell. In the state of being connected in series, the current flowing through each unit cell is equal, but the remaining capacity of each unit cell always varies, so that the terminal voltage of each unit cell also differs. This variation in the remaining capacity is mainly caused by a difference in self-discharge and charge / discharge efficiency of each cell, and is accumulated and expanded with time.

That is, even if the charging is controlled by monitoring the total voltage between the terminals of the assembled battery, the terminal voltage of each unit cell as a component of the assembled battery is (voltage between terminals of the assembled battery) /
Some are higher or lower than the average voltage obtained by (number of unit cells). Therefore, there is a unit cell that is overcharged when charged to the upper limit voltage and overdischarged when discharged to the lower limit voltage.

[0010] In the case of NiCd or NiMH batteries, even if overdischarge or overcharge occurs, there is little deterioration in performance.
In addition, since the lead battery has no problem in safety even if its performance is deteriorated, and it is not possible to use any of them, it is sufficient to control the lead battery only with reference to the voltage across the assembled battery. However, when using a lithium battery as a multi-series battery pack, it is necessary to take measures to prevent each unit cell from being overcharged or overdischarged, that is, to prevent occurrence of abnormalities such as overcharge and overdischarge. It is essential to detect and judge.

[0011]

As a countermeasure for such a countermeasure, there is, for example, one disclosed in Japanese Utility Model Laid-Open No. 2-136445. In this prior art, as shown in FIG. 23, each unit cell 1 is connected in parallel with a voltage detector 2 for individually detecting each terminal voltage. The CPU 3 converts the detection signals of the respective voltage detectors 2 into multiplexers (MPX) 4 and 5 and an A / D converter 6.
Is to get through.

The CPU 3 detects the highest value among the terminal voltages of the unit cells 1 during charging and controls the highest voltage so as not to exceed the upper limit voltage, and detects the same lowest value during discharging. Then, when the minimum voltage reaches the lower limit voltage, control is performed so as to end the discharge.

However, in such a system, a voltage detector 2 must be provided for each unit cell 1 in order to monitor the occurrence of overcharge or overdischarge. In order to process a large number of detection signals output from each voltage detector 2, multiplexers 4 and 5 are required. In addition, since the number of wirings from the unit cell 1 to the voltage detector 2 increases, there is a problem that the cost generally increases.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an apparatus or a method for judging an abnormality occurring in a battery pack when performing charge / discharge control of the battery pack. Configuration or implementation at cost.

[0015]

According to the present invention, there is provided a battery pack abnormality judging apparatus, wherein a plurality of unit cells each composed of a secondary battery are connected in series to form a cell group. For the assembled batteries configured by connecting in series, each abnormality detecting means detects occurrence of an abnormal state for each cell group. The voltage output means changes the output voltage when the abnormality detection means detects an abnormal state,
The abnormality determining means determines that an abnormality has occurred in the unit cells constituting the cell group when a change in the output voltage of the voltage output means is detected by the voltage detecting means.

That is, the abnormality judging means does not need to individually monitor the unit cells constituting the battery pack, but monitors the voltage change of each cell group by the voltage output means for each cell group as a unit. The occurrence may be determined. Therefore, it is possible to simplify the configuration by reducing the monitoring load of the abnormality determination unit, and it is possible to configure the apparatus at low cost.

According to the second aspect of the present invention, the voltage output means can change the terminal voltage of at least one unit cell constituting the corresponding cell group as its own output voltage. Therefore, the voltage output means can be configured using simple components. In addition, since the voltage detecting means directly monitors the terminal voltage of one or more unit cells in a normal state, it is necessary to obtain information necessary for charge / discharge control of the assembled battery from the detection output of the voltage detecting means. Can also.

According to the third aspect of the present invention, the voltage output means is configured to be able to change the terminal voltage of the corresponding cell group as its own output voltage. The terminal voltage of the cell group is directly monitored, and information necessary for charge / discharge control of the assembled battery or the like can be obtained from the detected output on a cell group basis.

According to the fourth aspect of the present invention, the abnormality detecting means compares the terminal voltage of each unit cell constituting the cell group with the lower limit voltage, and determines the terminal voltage of any one of the unit cells. Is detected when the voltage falls below the lower limit voltage. That is, when the battery pack is discharged, the terminal voltage of each unit cell gradually decreases, but when the terminal voltage falls below the lower limit voltage defined as the usable range, the unit cell enters an overdischarged state. Therefore, with this configuration, the overdischarge state of the unit cell can be detected as abnormal.

According to the apparatus for judging abnormality of a battery pack according to the fifth aspect, the abnormality detecting means compares the terminal voltage of each unit cell constituting the cell group with the upper limit voltage and determines the terminal voltage of any one of the unit cells. Is detected when the voltage exceeds the upper limit voltage. That is, when the battery pack is charged, the terminal voltage of each unit cell gradually increases, but when the terminal voltage rises above an upper limit voltage defined as a usable range, the unit cell is in an overcharged state. Therefore, with this configuration, the overcharged state of the unit cell can be detected as abnormal.

According to the apparatus for judging abnormality of an assembled battery according to claim 6, the abnormality detecting means detects at least one temperature of each unit cell constituting the cell group, compares the temperature with a reference temperature, and detects the temperature. An error is detected when the temperature exceeds the reference temperature. That is, with such a configuration, when the battery pack is charged or discharged, a case where the temperature of any of the unit cells becomes excessively high in which the temperature of the unit cell abnormally increases can be detected as abnormal.

According to the apparatus for judging abnormality of a battery pack according to the present invention, the temperature detecting means is the same as the number of the unit cells constituting the cell group, and each positive thermistor is connected to the positive terminal of the cell group. And a positive voltage detection line of the cell group, and are inserted in series and arranged near each unit cell.

For example, when an abnormality occurs in the unit cell and the temperature rises significantly beyond a certain level, the resistance value of the positive thermistor also increases, and the positive voltage detection line is opened. Therefore, as a result, the abnormality detecting means, the temperature detecting means, the temperature comparing means, and the voltage output means are commonly configured by the positive thermistor, so that the configuration can be greatly simplified.

According to the apparatus for judging abnormality of an assembled battery according to claim 8, the abnormality detecting means detects the concentration of the gas leaking from the unit cell in the cell group and compares it with the reference concentration. If the value exceeds the reference concentration, an abnormality is detected. That is, since a secondary battery is generally configured using an electrolytic solution or the like, gas is generated internally by an electrolytic action during charging and discharging. If a part of the unit cell housing is damaged for some reason, the gas generated inside leaks out. Therefore, with this configuration, it is possible to detect leakage of gas or breakage of the housing of the unit cell as an abnormality.

According to the battery pack abnormality judging device according to the ninth aspect, the voltage output means sets the output voltage to 0 V when the abnormality detecting means detects an abnormal state, so that the abnormality judging means easily judges the abnormality. be able to.

According to the apparatus for judging abnormality of a battery pack according to the tenth aspect, the voltage output means periodically changes the output voltage when the abnormality detection means detects an abnormal state. In other words, even when an abnormality is detected, the abnormality determination means can intermittently refer to the output voltage, and when the abnormal state gradually disappears due to the lapse of time from the occurrence of the abnormality, , You can grasp the situation.

According to the apparatus for judging abnormality of an assembled battery according to the eleventh aspect, the voltage output means changes the fluctuation cycle of the output voltage in accordance with the type of abnormal state detected by the abnormality detection means. Thus, it is possible to determine the type of abnormal state that has occurred according to the fluctuation cycle of the output voltage.

According to the apparatus for judging abnormality of a battery pack according to the twelfth aspect, the voltage output means changes the fluctuation cycle of the output voltage in accordance with the position of the unit cell in which the abnormal state is detected by the abnormality detecting means. The abnormality determining means can also determine at which position in the cell group the unit cell in which the abnormality has occurred is determined by the output voltage fluctuation cycle.

According to the battery pack abnormality judging device according to the thirteenth aspect, the voltage output means changes the output voltage in accordance with the type of the abnormal state detected by the abnormality detecting means. It is possible to determine the type of abnormal state that has occurred according to the voltage level.

According to the apparatus for judging abnormality of a battery pack according to the present invention, the voltage output means changes the output voltage in accordance with the position of the unit cell in which the abnormal state is detected by the abnormality detecting means. The means can also determine at which position in the cell group the unit cell in which the abnormality has occurred is based on the change level of the output voltage.

According to the apparatus for judging abnormality of a battery pack according to claim 15, when the abnormality detecting means detects an abnormal state, the voltage output means outputs the output voltage of the cell group in which the abnormal state is detected to the cell group. In the above, the potential is changed so as to be equal to the potential of the negative electrode of the unit cell where the abnormality is detected.
Therefore, the terminal voltage of the cell group changes to a level corresponding to the position of the unit cell in which the abnormal state is detected, so that the abnormality determining means easily determines which unit cell of the cell group has an abnormality. be able to.

According to the apparatus for judging abnormality of a battery pack according to the sixteenth aspect, the abnormality detecting device is constituted by the abnormality detecting means and the voltage change detecting means, and two wires are provided between the abnormality detecting apparatus and the voltage detecting means. Therefore, the number of wirings can be reduced, and the assembly cost can be further reduced.

According to the apparatus for judging abnormality of a battery pack according to the seventeenth aspect, the current flowing from the corresponding cell group to the voltage detecting means is detected and compared with the reference current value, and the detected current exceeds the reference current value. In this case, the current flowing through the voltage detecting means is interrupted by the current interrupting means. That is, if an abnormality such as a short circuit occurs on the external circuit side connected to the battery pack and an overcurrent flows from the cell group to the voltage detection means, the current is cut off to stop the battery pack or the battery. External circuits can be protected.

According to the apparatus for judging abnormality of a battery pack according to the eighteenth aspect, the abnormality detecting means and the voltage change detecting means obtain the operating power from the cell group. That is, these means
Any of them can be configured without using an element having large power consumption such as a CPU, and there is no problem even if the power supply voltage slightly varies. Therefore, it is not necessary to prepare a separate power supply by directly obtaining a power supply for operation from a cell group whose output voltage level is also appropriate as compared with the assembled battery,
It can be configured at lower cost.

According to the apparatus for judging abnormality of a battery pack according to the nineteenth aspect, the abnormality detecting means and the voltage change detecting means are provided with a unit cell constituting a cell group, a housing for accommodating the cell group, or a housing for forming the housing. Since it is integrated with the parts to be assembled, the assembling work becomes easy.

According to the apparatus for judging abnormality of a battery pack according to the twentieth aspect, the abnormality detecting means and the voltage change detecting means are integrated with the voltage adjusting means for adjusting the variation of the terminal voltage between the unit cells as much as possible. To be configured. That is, in an assembled battery formed by connecting a number of unit cells in series, if the terminal voltage varies among the unit cells, the efficiency of the battery decreases. Therefore, such a variation can be adjusted by the voltage adjusting means to improve the efficiency of the assembled battery, and by integrating it with the abnormality detecting means and the voltage change detecting means, the configuration is complicated due to the addition of the function. Can be avoided as much as possible.

According to the battery pack abnormality judging device of the present invention, the inter-group voltage adjusting means adjusts the variation of the output voltage between the cell groups as much as possible, thereby further improving the efficiency of the assembled battery. Can be improved.

According to the abnormality determination apparatus for a battery pack of the present invention, the present invention is applied to a battery pack having a unit cell of a lithium battery having a high energy density but requiring more strict measures for overcharge and overdischarge. By doing so, the performance of the lithium battery can be sufficiently extracted and used while safely controlling the charge and discharge.

According to the battery pack abnormality judging device of the present invention, since lithium nickel oxide is used as the active material for the positive electrode of the lithium battery, the voltage change between the normal use range and the overcharge-overdischarge range. Can be used in a state where charging and discharging are safely controlled, despite the fact that overcharging and overdischarging of the cell are difficult to determine from changes in the terminal voltage of the cell group.

According to the battery pack abnormality judging device according to claim 24 or 25, the battery pack is connected to an electric vehicle (claim 2).
4) Since the driving battery is used for the hybrid electric vehicle (claim 25), the use efficiency of the driving battery can be sufficiently improved.

[0041]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment)
A first embodiment when applied to a drive battery of a hybrid electric vehicle (HEV) will be described with reference to FIGS. In FIG. 1 showing the outline of the electrical configuration,
The unit cells 11 each composed of a lithium secondary battery form a cell group 12 for every four cells (C1 to C4) connected in series. For the positive electrode of the unit cell 11, lithium nickel oxide is used as an active material. Then, between the positive electrode 12p and the negative electrode 12n of each cell group 12, an abnormality detecting device 13 and a voltage detector (voltage detecting means)
14 are connected in parallel. The detection signal of each voltage detector 14 is provided to a CPU (abnormality determination means, voltage control means) 17 via a multiplexer (MPX) 15 and an A / D converter 16.

The CPU 17 supplies a switching control signal to each multiplexer 15 to sequentially refer to the terminal voltage VG of each cell group 12 detected by the voltage detector 14. Further, the CPU 17 writes and stores data in a memory 18 such as a RAM, and reads out the data as necessary.

In the cell group 12, 20 batteries are connected in series to form a battery pack 19, and the battery pack 19 is
A positive electrode 19p and a negative electrode 19 are used as HEV driving batteries.
n is connected via a main current path L +, L- to a charger, an inverter (not shown) for driving an HEV motor, or the like.

FIG. 2 shows a detailed electrical configuration of the abnormality detecting device 13. The unit cell 11 (C1) will be described.
A series circuit of Oa and 20b, a series circuit of a resistor 21 and a Zener diode 22, and a series circuit of a resistor 23 and a Zener diode 24 are connected in parallel. The common connection point VD of the voltage dividing resistors 20a and 20b is
Connected to the non-inverting input terminal of the
Is connected to the inverting input terminal of the comparator 27 via the.

The resistor 21 and the Zener diode 2
The common connection point VL of the two is connected to the inverting input terminal of the comparator 25 via the resistor 28a, and the common connection point VH of the resistor 23 and the zener diode 24 is connected to the non-inverting input terminal of the comparator 27. . The output terminal of the comparator 25 is connected to its own inverting input terminal via a resistor 28b, and is also connected to the input terminal of a 9-input AND gate (abnormality detection means) 29. It is connected to its own inverting input terminal via a resistor 26b and to another input terminal of the AND gate 29.

The comparator 25 outputs a high level when the level of the common connection point VD is higher than the level of the common connection point VL determined by the zener voltage VZ1 of the zener diode 22, and outputs a low level when the level is low. The Zener voltage VZ1 is set to a value obtained by multiplying the lower limit voltage VLL of the lithium secondary battery by the voltage dividing ratio of the resistors 20a and 20b.

That is, the output level of the comparator 25 is
At the time of discharging the battery pack 19, it becomes "H" when the terminal voltage VC of the unit cell 11 is higher than the lower limit voltage VLL, and becomes "L" when an overdischarge state becomes lower than the lower limit voltage VLL. The resistors 20a and 20b, the resistor 21, the Zener diode 22, the comparator 25, and the resistors 28a and 2
8b constitutes a lower limit voltage detection circuit (abnormality detection means, lower limit voltage comparison means) 30.

On the other hand, the comparator 27 is connected to the common connection point V
If the level of D is lower than the level of the common connection point VH determined by the Zener voltage VZ2 of the Zener diode 24, a high level is output, and if it is higher, a low level is output. The Zener voltage VZ2 is set to a value obtained by multiplying the upper limit voltage VHL of the lithium secondary battery by the voltage dividing ratio of the resistors 20a and 20b.

That is, the output level of the comparator 27 is
At the time of charging the battery pack 19, the voltage becomes "H" when the terminal voltage VC of the unit cell 11 is lower than the lower limit voltage VHL, and becomes "L" when an overcharge state exceeding the lower limit voltage VHL occurs. The resistors 20a and 20b, the resistor 23 and the zener diode 24, the resistors 26a and 26b, and the comparator 27 constitute an upper limit voltage detection circuit (abnormality detection means, upper limit voltage comparison means) 31. Note that other unit cells 11
The same applies to the configuration related to (C2 to C4), and (2) to (4) are added instead of (1) of C1.

A series circuit of resistors 32a and 32b and a series circuit of a resistor 33 and a (positive) thermistor 34 are connected in parallel between the positive electrode 12p and the negative electrode 12n of the cell group 12. And resistors 32a, 32b
Are connected to the non-inverting input terminal of the comparator 35, and the common connecting point of the resistor 33 and the thermistor (temperature detecting means) 34 is connected to the inverting input terminal of the comparator 35 via the resistor 36a. I have. The output terminal of the comparator 35 is connected to its own inverting input terminal via the resistor 36b and to the input terminal of the AND gate 29.

The thermistor 34 is connected to one of the unit cells 11
(For example, C1) and the unit cell 1
The resistance value increases and decreases as the temperature of 1 rises and falls. The resistances of the resistor 32a and the resistor 33 are set equal, and the resistance of the resistor 32b is set equal to the resistance of the thermistor 34 when the temperature of the unit cell 11 reaches the upper limit temperature.

The comparator 35 compares the terminal voltage VTH of the thermistor 34 with the terminal voltage VR of the resistor 32b, and outputs "H" if VTH <VR, so that the temperature of the unit cell 11 becomes lower than the upper limit temperature. When VTH> VR due to an excessively high temperature state, "L" is output. The resistor 32a
, 32b, the resistor 33 and the thermistor 34, the comparator 35, the resistor 36a and the resistor 36b constitute an overheating detecting circuit (abnormality detecting means, temperature comparing means) 37.

The positive electrode 12p of the cell group 12 is connected to a fixed contact 38a of a switch (voltage changing means) 38, and the movable contact 38b is connected to a positive voltage detection line W +. Then, the negative electrode 12n of the cell group 12
Is directly connected to the negative voltage detection line W−.

The output terminal of the AND gate 29 is connected to the control terminal of the switch 38.
If the control signal supplied from the ND gate 29 is "H", the movable contact 38b is connected to the fixed contact 38a, and if the control signal is "L", the movable contact 38b and the fixed contact 38 are connected.
a is opened.

In the above description, the control unit 39 of the assembled battery 19 except for the assembled battery 19 and the abnormality detecting device 13 is formed. Power for operating the comparators 25, 27 and 35 and the AND gate 29 which constitute the abnormality detection device 13 is obtained from the cell group 12. Further, when the HEV runs, the CPU 17 also controls the charging and discharging of the battery pack 19 as a driving battery by giving a control signal to a control device (neither is shown) of an inverter that drives the driving motor when the HEV runs. It is configured to be. Therefore, the control unit 39 also has a function as a charge / discharge control device (voltage control device) for the battery pack 19.

Next, the operation of the present embodiment will be described with reference to FIG. The AND gate 29 outputs “H” when the levels of all the input terminals are “H”, and outputs “L” when any one of the levels of the input terminals is “L”. That is, when the HEV is running, if there is no abnormality in the battery pack 19, the AND gate 29 outputs "H", and the switch 38 connects the movable contact 38b to the fixed contact 38a. Therefore, the voltage detector 14 includes:
The output voltage of the cell group 12 is given as E4 (V), which is the sum of the terminal voltages of the four unit cells 11.

The HEV drives the motor at the time of start or at the time of low-speed operation, so that the assembled battery 19 is discharged. In addition, during high-speed operation, the vehicle is driven by driving a gasoline engine, and the battery pack 19 is charged.

At time t1 shown in FIG. 3, the battery pack 19 is in an overcharged state during charging, an overdischarged state during discharging, or an excessively high temperature due to an abnormal rise in the temperature of the battery pack 19. If any of the above conditions occur, A
The ND gate 29 outputs “L”. Then, the switch 38 separates the movable contact 38b and the fixed contact 38a, so that a high impedance is applied between the voltage detection lines W + and W-, and the cell group 12 supplied to the voltage detector 14 becomes high impedance.
Changes from E4 (V) to 0 (V). CP
U17 determines that an abnormal state has occurred in the cell group 12 due to the change in the output voltage, and performs a predetermined process such as outputting a signal to a control device of the inverter so as to control charging or discharging power. .

As described above, according to the present embodiment, a plurality of unit cells 11 composed of lithium secondary batteries are connected in series to form a cell group 12, and a plurality of the cell groups 12 are connected in series. An abnormality detecting device 1 is formed between each cell group 12 and the voltage detector 14 by constituting a battery pack 19.
3 was placed. Then, the lower limit voltage detecting circuit 30, the upper limit voltage detecting circuit 31, and the overheating detecting circuit 37 constituting the abnormality detecting device 13 cause overdischarging, overcharging or overheating of each unit cell 11 constituting the cell group 12. When detecting an abnormal state such as, for example, the AND gate 29 uses the switch 38 to change the terminal voltage of the cell group 12 to E4.
(V) was changed to 0 (V).

Accordingly, each abnormality detecting device 13 and the control unit 39
Between the two voltage detectors W + and W
The CPU 17 can determine that an abnormality has occurred in the unit cells in each of the cell groups 12 by simply connecting them with a minus sign, so that the number of electronic components for controlling the battery pack 19 such as the voltage detector 14 and the like can be reduced. Can be greatly reduced, and the cost of the control unit 39 can be reduced. In addition, the operator can check each abnormality detection device 13 and the control unit 39.
Can be easily connected.

According to the present embodiment, the abnormality detecting device 1
3 is configured without using a CPU or the like, and its operating power is obtained from each cell group 12. That is,
Since the power consumption of the abnormality detection device 13 is extremely small, and the cell group 12 has a 4-series configuration, the terminal voltage is about 3.6 × 4 = 14.4 (V), that is, 3.3 to 5 V.
It is suitable for the creation of a power supply for operation.

Since the abnormality detection device 13 can operate even if the power supply voltage is slightly lowered, a sufficiently stable operation can be performed even if the operation power supply is obtained from the cell group 12. Therefore, it is possible to suppress the power consumption of the control power supply (so-called battery) having a relatively small capacity with respect to the operation power supply.

Further, according to this embodiment, a lithium battery having a high energy density but requiring more strict measures for overcharging and overdischarging is applied to the assembled battery 19 as the unit cell 11, whereby It is possible to take full advantage of the performance of a lithium battery while safely controlling charging and discharging, and utilize it. Particularly effective for batteries in which the voltage change between the normal use range and the overcharge-overdischarge range is relatively slow, such as a lithium battery using lithium nickel oxide as an active material for the positive electrode. It is.

In other words, the inventor of the present invention has found that the voltage change in the overcharge and overdischarge regions, such as in a lithium secondary battery using lithium manganese oxide for the positive electrode in the past for the same purpose and effect, is greater than that in the normal use region. Japanese Patent Application No. Hei 10-301265 proposes an invention in which overcharging and overdischarging of each cell is determined from a change in the terminal voltage of a cell group by utilizing a sudden characteristic. On the other hand, the present invention reliably detects overcharge and overdischarge as abnormal in a lithium secondary battery using a lithium nickel oxide having no such remarkable voltage change characteristics as a positive electrode.

In addition, according to the present embodiment, by using the assembled battery 19 for the HEV, each of the above-described effects is effectively achieved in a configuration in which many unit cells 11 are connected in series to obtain a high output. Can be applied to

Further, according to the present embodiment, the voltage output means is simply constituted by using the switch 38, and the terminal voltage VG of the corresponding cell group 12 can be changed to 0 V as its own output voltage. The detector 14 directly monitors the terminal voltage VG of the cell group 12 during normal operation. Therefore, the CPU 17 can also obtain information necessary for charge / discharge control and the like of the battery pack 11 on a cell group basis from the detection output of the voltage detector 14. Since the voltage detector 14 can be used for both abnormality determination and charge / discharge control, the configuration can be further simplified.

(Second Embodiment) FIGS. 4 and 5 show a second embodiment of the present invention. The same parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. Only the parts will be described. In the second embodiment, four overheating detection circuits 37 provided corresponding to one unit cell 11 (C1) in the first embodiment are provided (37 (1) to 37 (37)).
(4)), the remaining three unit cells 11 (C2 to C4) are also arranged correspondingly.

Further, instead of the 9-input AND gate 29,
3-input AN corresponding to each of the four unit cells 11
D gates (abnormality detecting means) 40 (1) to 40 (4) are provided, and the lower limit voltage detecting circuit 3 of each unit cell 11 is provided.
Output terminals of the 0, upper limit voltage detection circuit 31 and the excessive temperature rise detection circuit 37 are connected to input terminals of the respective AND gates 40.

The switch 38 in the first embodiment is designated as 38A (1), and three switches 38A are provided between the switch 38A (1) and the positive electrode of the cell group 12.
(2) to 38A (4) are connected in series. The output terminals of the AND gates 40 (1) to 40 (4) are connected to the control input terminals of the switches 38A (1) to 38A (4), respectively. When the switch 38A is turned off by separating the fixed contact 38a and the movable contact 38b, the switch 38A connects the movable contact 38b to the corresponding terminal cell 11.
Of the negative electrode 11n. More than,
The abnormality detection device 41 is configured.

Next, the operation of the second embodiment will be described with reference to FIG. In the second embodiment, an abnormal state such as overdischarge, overcharge or overheating is detected for each unit cell 11. For example, as shown in FIG. 5, when any of the above abnormal states occurs in the unit cell 11 (C4) at time t1, the output terminal of the AND gate 40 (4) becomes "L" and the switch 38A (4) Is turned off, and the voltage detection line W + is connected to the negative electrode 1 of the unit cell 11 (C4).
1n.

Then, the output voltage of the cell group 12 detected by the voltage detector 14 becomes equal to the unit cell 11 (C
4) The voltage decreases by one to become the sum of the terminal voltages of the unit cells 11 (C1 to C3), and changes from E4 (V) to E3 (V). After the abnormal state is resolved at time t2, if any of the abnormal states described above occurs in the unit cell 11 (C3) at time t3, the output terminal of the AND gate 40 (3) becomes "L" and the voltage detection is performed. The line W + is connected to the negative electrode 11 of the unit cell 11 (C3) through the switch 38A (3).
n. Then, the output voltage detected by the voltage detector 14 is the sum of the terminal voltages of the unit cells 11 (C1, C2), and changes from E4 (V) to E2 (V).

Similarly, after the abnormal state is resolved at time t4, if any of the above abnormal states occurs in unit cell 11 (C2) at time t5, AND gate 40
The output terminal of (2) becomes “L”, and the voltage detection line W +
It is connected to the negative electrode 11n of the unit cell 11 (C2) via the switch 38A (2). Then, the output voltage detected by the voltage detector 14 becomes the terminal voltage of the unit cell 11 (C1), and changes from E4 (V) to E1 (V). After the abnormal state is resolved at time t6,
When any of the abnormal states described above occurs in the unit cell 11 (C1) at time t7, the voltage detection line W + is connected to the negative electrode 12n of the cell group 12, and E4 (V) as in the first embodiment. To 0 (V).

Therefore, according to the second embodiment configured as described above, the CPU 17 determines which one of the cell groups 12 is to be configured according to the change in the output voltage of the cell group 12 obtained from the voltage detector 14. It can be determined whether or not an abnormal state has occurred in the unit cell 11.

(Third Embodiment) FIG. 6 shows a third embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. explain. The abnormality detection device 42 of the third embodiment is different from the abnormality detection device 13 of the first embodiment in that a gas leak detection circuit (abnormality detection means, gas concentration comparison means) 43 and an overcurrent detection circuit (abnormality detection means, overcurrent detection (Means) 44.

In FIG. 6 showing the electrical configuration of the main part, the gas leak detection circuit 43 is configured around a comparator 45. Both electrodes 12p, 1 of cell group 12
A series circuit of the resistors 46a and 46b is connected between 2n, and a common connection point between the two is connected to a non-inverting input terminal of the comparator 45. The power supply terminal 47a and the ground electrode 47b of the gas sensor (gas concentration detecting means) 47 are connected to the positive electrode 12p and the negative electrode 12 of the cell group 12.
n, and an output terminal 47c is connected to a resistor 48.
It is connected to the inverting input terminal of the comparator 45 via a. A resistor 49 is connected between the power supply terminal 47a and the output terminal 47c.

The output terminal of the comparator 45 is connected to the input terminal of an 11-input AND gate (abnormality detecting means) 50 instead of the AND gate 29, and the resistance 48
b is connected to its own inverting input terminal. The gas sensor 47 is a sensor for detecting an organic gas composed of a semiconductor or the like, and the output voltage increases as the gas concentration increases. And resistance 4
The partial pressure ratio of 6a and 46b is set according to the output voltage of the gas sensor 47 according to the upper limit concentration value of the gas.

On the other hand, the overcurrent detection circuit 44 is configured around a comparator 51. A shunt resistor for current detection (output current detection means) is provided between the movable contact 38b of the switch (current cutoff means) 38 and the voltage detection line W +.
52 is interposed. Between the terminal 52 a of the resistor 52 on the switch 38 side and the negative electrode 12 n of the cell group 12,
A series circuit of resistors 53a and 53b is connected, and a common connection point between the two is connected to a comparator 5 via a resistor 54a.
1 inverting input terminal.

The other terminal 52b of the resistor 52 is connected to the non-inverting input terminal of the comparator 51 and to the negative electrode 12n via the resistor 55. The output terminal of the comparator 51 is connected to the input terminal of the AND gate 50 and to its own inverting input terminal via the resistor 54b. And the resistor 53a
And 53b are set in accordance with the potential appearing at the common connection point of resistors 52 and 54a according to the upper limit of the current flowing through voltage detection line W +. Other configurations are first
This is the same as the embodiment.

Next, the operation of the third embodiment will be described. The lithium secondary battery constituting the unit cell 11 uses an organic electrolytic solution. Therefore, for example, when the internal pressure of a case (not shown) containing the cell group 12 is increased and the case is damaged, an organic gas is released to the outside.

In this case, when the gas sensor 47 detects an increase in the gas concentration and the output voltage increases, and the gas concentration exceeds the upper limit concentration value, the output level of the comparator 45 changes from “H” to “L”. Then, the output level of the AND gate 50 also changes from "H" to "L", and the output voltage of the cell group 12 is changed from E4 (V) to 0 (V) by opening the switch 38 as in the first embodiment. Changes to

Further, for example, if the voltage detection lines W + and W- are short-circuited due to breakage of the coating or the like, an excessive discharge current flows from the cell group 12 and may be destroyed. In such a case, when the current flowing through the voltage detection line W + exceeds the upper limit, the output level of the comparator 51 becomes “H”.
From "H" to "L", and the output level of the AND gate 50 also changes from "H" to "L". Then, cell group 1
The output voltage of No. 2 changes from E4 (V) to 0 (V).

As described above, according to the third embodiment, since the abnormality detection device 42 is provided with the gas leak detection circuit 43 and the overcurrent detection circuit 44, the storage case of the cell group 12 is damaged, The cell group 12 can be protected by detecting an abnormal state such as a short circuit between the detection lines W + and W− and an overcurrent flowing. When an overcurrent flows, the switch 38 is opened to open the cell group 12.
External circuits such as the voltage detector 14 connected to the power supply can also be protected.

(Fourth Embodiment) FIGS. 7 and 8 show a fourth embodiment of the present invention. The same parts as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. Only the parts will be described. The abnormality detection device 56 of the fourth embodiment includes an INV (inverter) gate 57a, a multivibrator (MV) 57b, and an OR gate between the output terminal of the AND gate 29 and the control terminal of the switch 38 in the first embodiment.
An oscillation circuit (voltage changing means) 57 constituted by a gate 57c is interposed.

The output terminal of the AND gate 29 is connected to the input terminals of the INV gate 57a and the OR gate 57c, and the output terminal of the OR gate 57c is connected to the switch 38.
Is connected to the control terminal. An output terminal of the INV gate 57a is connected to a trigger input terminal of the multivibrator 57b, and an output terminal of the multivibrator 57b is connected to a different input terminal of the OR gate 57c. The multivibrator 57b outputs an oscillation signal of a predetermined frequency when the level of the trigger input terminal becomes "H". Other configurations are the same as in the first embodiment.

Next, the operation of the fourth embodiment will be described with reference to FIG. As shown in FIG.
2 is in a normal state from time 0 to t1.
Since the output level of the D gate 29 is "H", the signal applied to the control terminal of the switch 38 via the OR gate 57c is also "H", and the switch 38 is closed. Further, the multivibrator 5 is connected via the INV gate 57a.
The level given to the trigger input terminal 7b is "L"
Therefore, the multivibrator 57b does not oscillate.

At time t1, when an abnormal state such as overdischarge, overcharge or overheating is detected and the output level of the AND gate 29 becomes "L", the level of the trigger input terminal of the multivibrator 57b becomes "L". H ", the multivibrator 57b performs an oscillating operation and outputs an oscillating signal. Then, the switch 38 repeats opening and closing according to the frequency of the oscillation signal (switching).
The output voltage of the cell group 12 periodically fluctuates between E4 (V) ← → 0V. Therefore, the CPU 17 determines at time t1
, The output voltage of the cell group 12 is obtained intermittently during a period from time t2 to time t2 when the abnormal state is resolved.

That is, according to the fourth embodiment configured as described above, the CPU 17 can intermittently obtain the output voltage of the cell group 12 while the cell group 12 is abnormal. Therefore, it is possible to determine that an abnormality has occurred in the cell group 12 based on the fluctuation of the output voltage level, and it is also possible to detect the output voltage level of the cell group 12 during the period in which the abnormality has occurred.
Therefore, unlike the first embodiment, it is possible to grasp the change in the output voltage of the cell group 12 during the period.

(Fifth Embodiment) FIGS. 9 and 10 show a fifth embodiment of the present invention. The same parts as those of the second or fourth embodiment are denoted by the same reference numerals, and the description thereof is omitted. Hereinafter, only different portions will be described. The abnormality detecting device 58 of the fifth embodiment includes three four-input AND gates instead of the four three-input AND gates 40 (1) to 40 (4) in the second embodiment.
Gate (abnormality detection means) 59 (D), 59 (C), 59
(T) is arranged.

The output terminals of the overdischarge detection circuits 30 (1) to 30 (4) corresponding to the unit cells 11 (1) to 11 (4) are connected to the input terminals of the AND gate 59 (D), respectively. It is connected. Similarly, the input terminals of the AND gate 59 (C) are similarly connected to the overcharge detection circuits 31 (1) to 31 (31).
The output terminals of (4) are connected to each other, and the input terminal of the AND gate 59 (T) is connected to the overheating detection circuit 37 (1).
To 37 (4) are connected respectively.

AND gates 59 (D), 59 (C), 5
9 (T) output terminals are each an oscillation circuit (voltage changing means)
3 inputs A via 60 (D), 60 (C), 60 (T)
The input terminals of the ND gate (voltage changing means) 61 are connected to each other, and the output terminal of the AND gate 61 is connected to the control terminal of the switch 38. Each oscillation circuit 60
The configurations of (D), 60 (C), and 60 (T) are basically the same as the configuration of the oscillation circuit 57 in the fourth embodiment, but each has a built-in multivibrator (not shown). Have different oscillation frequencies fD, fC, and fT, for example, fD>fC> fT.

Next, the operation of the fifth embodiment will be described with reference to FIG. As shown in FIG. 10, the period from time 0 to t1 when the cell group 12 is in the normal state is:
Since the output levels of the AND gates 59 (D), 59 (C) and 59 (T) are all "H", the oscillation circuit 60
(D), 60 (C), 60 (T) and AND gate 61
Is also at "H", and the switch 38 is closed.

When the overdischarge is detected by any of the overdischarge detection circuits 30 (1) to 30 (4) at time t1, the output level of the AND gate 59 (D) becomes "L". Then, the oscillating circuit 60 (D) oscillates, and the switch 38 sets the frequency fD of the oscillating signal.
Is switched in accordance with. Therefore, cell group 1
2 has a frequency fD between E4 (V) and 0V.
Fluctuates periodically.

After the overdischarge state is eliminated at time t2, overcharge detection circuits 31 (1) -31 at time t3.
When overcharge is detected by any of (4), AND
Since the output level of the gate 59 (C) becomes "L" and the oscillation circuit 60 (C) oscillates, the switch 38 is switched according to the frequency fC of the oscillation signal. After the overdischarge state is eliminated at time t4, if any of the overheating detection circuits 37 (1) to 37 (4) detects an overheating at time t5, the AND gate 5
9 (T) becomes “L” and the oscillation circuit 60
Since (T) oscillates, the switch 38 is switched according to the frequency fT of the oscillation signal.

That is, according to the fifth embodiment configured as described above, the CPU 17 switches the output voltage of the cell group 12 obtained from the voltage detector 14 due to the occurrence of the abnormal state, and becomes intermittent. In this case, the type of abnormality that has occurred can be identified by detecting the switching frequency.

(Sixth Embodiment) FIGS. 11 to 13 show a sixth embodiment of the present invention. The same parts as those of the second embodiment are denoted by the same reference numerals, and the description thereof will be omitted. Only the parts will be described. Abnormality detection device 62 of the fifth embodiment
Is obtained by adding a voltage adjusting circuit (voltage adjusting means) 63 to the configuration of the abnormality detecting device 41 of the second embodiment. In FIG. 11, the voltage adjustment circuit 63 includes each unit cell 11
The positive electrode 11p and the negative electrode 11n of (1) to 11 (4) are connected respectively.

FIG. 12 shows a detailed electrical configuration of the voltage adjusting circuit 63. The voltage adjusting circuit 63 includes a voltage dividing circuit 64 composed of four resistors connected in series to divide the terminal voltage of the cell group 12 into four equal parts, and the voltage dividing circuit 6
4, differential amplifiers 65 (1), 65 for differentially amplifying the difference between the potential of the three voltage dividing points Jr1, Jr2, Jr3 and the potential of the connection terminals Jc1, Jc2, Jc3 of the corresponding cell group 12.
(2), 65 (3), differential amplifiers 65 (1) to 65 (65)
The output signal of (3) is converted to a minute voltage VH according to the polarity of the polarity.
, VL for comparison with the comparator 66H (1),
66L (1) to 66H (3), 66L (3) and the output signals of the comparators 66H (1) to 66L (3) are set to INV,
Logic circuit 6 for performing logic synthesis by AND and OR gates
7. Discharge circuit 68 composed of a series circuit of a resistor and a switch controlled to open and close by an output signal of logic circuit section 67
(1) to 68 (4).

Here, in order to use the assembled battery 19 constituted by connecting the unit cells 11 composed of lithium secondary batteries in series with high efficiency, it is necessary to compare with the case where a lead battery or a Ni-MH battery is used. Then, it is necessary to more strictly adjust the variation of the terminal voltage between the unit cells 11. Voltage adjustment circuit 6
No. 3 realizes such a variation adjustment function only by hardware without performing software-based processing using a CPU, thereby reducing the size and cost of the circuit by eliminating the need for a peripheral circuit of the CPU. It is a thing.
The detailed operation of the voltage adjustment circuit 63 is disclosed in Japanese Patent Application No. 10-249841 or the like, and will not be described in detail here.

FIG. 13 shows a configuration of a control unit 69 replacing the control unit 39. That is, the voltage adjustment circuit 63 is provided between the voltage detection lines W + and W− of each cell group 12.
Similarly to the discharge circuit 68, a discharge circuit 70 composed of a series circuit of a resistor 70a and a switch 70b that is controlled to open and close by a control signal provided from a CPU 17a via a decoder 71 is connected.

Then, the CPU 17a closes the switch 70b of the discharge circuit 70 based on the value obtained from the voltage detector 14 corresponding to each output voltage variation between the cell groups 12, thereby causing the cell group 12 to change. The adjustment is made by discharging or by bypassing the charging current. The CPU 17a and the discharge circuit 7
0 and the decoder 71 constitute an inter-group voltage adjusting unit 72.

As described above, according to the sixth embodiment, the abnormality detecting device 62 is provided with the voltage adjusting circuit 63 so that each unit cell 1
Since the variation of the terminal voltage between the two is automatically adjusted by hardware, the battery pack 19 can be used with high efficiency, and an increase in the circuit size of the abnormality detection device 62 can be suppressed as much as possible. Also, a discharge circuit 70 is provided for each cell group 12 so that the CP
Since the variation of the output voltage between the cell groups 12 is adjusted by the U17a, the assembled battery 19 can be used with higher efficiency.

(Seventh Embodiment) FIG. 14 is a perspective view showing the appearance of a cell group 12 according to a seventh embodiment of the present invention. The unit cell 11 has a substantially cubic shape, and a positive terminal 11p and a negative terminal 11n are arranged on the upper surface thereof. Then, the four unit cells 11 (C1) to 11 (C
4) are arranged vertically and horizontally by two rows, and between each electrode, a conductor plate 73 is provided.
The cell groups 12 are connected in series by (0) to 73 (4). Incidentally, the conductor plates 73 (0), 7
3 (4) is the positive electrode 1 of another cell group 12 not shown.
2p and the negative electrode 12n.

In the center of the upper surface of the cell group 12, for example, a module of the abnormality detecting device 62 in the sixth embodiment is arranged.
9, only two voltage detection lines W + and W- are wired.

For example, in the conventional configuration, wiring from the same number of unit cells to the control unit requires five voltage detection lines and five temperature detection lines. On the other hand, according to the seventh embodiment, only two wires are required between each cell group 12 and the abnormality detection device 62 and the control unit 69, so that the wiring work can be saved. Assembly to the HEV can be easily performed.

(Eighth Embodiment) FIG. 15 shows an eighth embodiment of the present invention. The upper surface of the cell group 12 shown in the seventh embodiment is formed of an insulating material such as resin. In this configuration, a terminal cover (component) 74 is attached. On the back side of the terminal cover 74, each unit cell 11
Connection terminal 7 electrically connected to the electrodes 11p and 11n
5 (0) to 75 (4) are arranged, and the abnormality detection device 62 is arranged on the back side of the terminal cover 74.
The two voltage detection lines W + and W− are connected to the terminal cover 7.
4 is wired to the outside from the back side.

According to the eighth embodiment configured as described above, the terminal section on the upper surface of the cell group 12 is covered with the terminal cover 74, so that the occurrence of electric shock or short circuit during operation is prevented. be able to.

(Ninth Embodiment) FIG. 16 shows a ninth embodiment of the present invention, in which the cell group 12 shown in the seventh embodiment is formed of a housing made of an insulating material such as resin. The module battery 77 is housed inside the battery 76. On the upper surface side of the housing 76, only the conductor plates 73 (0) and 73 (4) are exposed to the outside for connection with another cell group 12, and two voltage detections are performed. Lines W + and W- are drawn out.

According to the ninth embodiment configured as described above, the handling can be facilitated by forming the cell group 12 into one module battery 77 together with the abnormality detecting device 62.

(Tenth Embodiment) FIG. 17 shows a tenth embodiment of the present invention.
It shows an embodiment. In the tenth embodiment, a unit cell 11A having a cylindrical shape is used in place of the square shape in the seventh to ninth embodiments. In the unit cell 11A, one positive electrode terminal 11Ap and one negative electrode terminal 11An are respectively disposed on two bottom surfaces of the cylinder. As shown in FIG. 17B, the four unit cells 11A have a cell holder 7 in which a square plate is provided with four holes 78a having a diameter corresponding to the diameter of the unit cells 11A.
8 is held.

Then, the unit cells 11A (C1) to 11A
The polarity of the terminal (C4) is arranged such that positive and negative alternate on one side. Therefore, FIG.
, The conductor plates 79 (0), 79 (2), 79 (4) are located on the near side, and the conductor plates 79 (1) (not shown), 79 (3) (see FIG. 17 (c)). Is located on the depth side.

The four unit cells 11A (C1) to 1
In the center portion surrounded by 1A (C4), an abnormality detection device 62A having a columnar shape with a diamond-shaped cross section is arranged. The cell holder 78 is also provided with a diamond-shaped hole 78b corresponding to the cross-sectional shape of the abnormality detection device 62A, and the cell holder 78 simultaneously holds the abnormality detection device 62A. Therefore, the electrical connection between the abnormality detection device 62A and the conductor plates 79 (0), 79 (2), 79 (4) is made on the near side, and the conductor plates 79 (1), 79 (4)
The electrical connection with (3) is made on the depth side. Further, the voltage detection lines W + and W− are drawn out from the end face on the depth side of the abnormality detection device 62A. The above constitutes the cell group 12A.

According to the tenth embodiment configured as described above, the cross-sectional shape of the abnormality detecting device 62A is rhombic, so that when four cylindrical unit cells 11A are collectively arranged, they are located at the central portion. The abnormality detection device 62A can be arranged by effectively utilizing the appearing dead space. Further, for example, when the cooling air flows in the direction of the arrow shown in FIG. 17B, the cooling air can be guided along the cylindrical surface of the unit cell 11A by the outer shape of the abnormality detection device 62A. The cooling efficiency of the group 12A can be improved.

(Eleventh Embodiment) FIG. 18 shows an eleventh embodiment of the present invention.
It shows an embodiment. The abnormality detection device 80 according to the eleventh embodiment includes four positive thermistors (an abnormality detection unit,
Temperature detecting means, temperature comparing means, voltage output means) 81
(1), 81 (2), 81 (3), 81 (4). These four thermistors 81 (1) to 81 (1) to
81 (4) is inserted in series between the positive terminal 12p of the cell group 12 and the voltage detection line W +. Each of the thermistors 81 (1) to 81 (4) is connected to each of the unit cells 11 (1) to 81 (4).
(C1) to 11 (C4), respectively.
These temperatures are detected.

Next, the operation of the eleventh embodiment will be described. When an abnormality occurs in any of the unit cells 11 (C1) to 11 (C4) and the temperature rises, the resistance value of the thermistor 81 corresponding to the unit cell 11 in which the abnormality has occurred increases accordingly. When the temperature of the unit cell 11 exceeds a certain value, the resistance value of the thermistor 81 becomes extremely large, so that the voltage detection line W + is opened. Then, the output voltage of the abnormality detection device 80 detected by the voltage detector 14 becomes substantially 0 V,
Can determine that an abnormality has occurred in the cell group 12.

As described above, according to the eleventh embodiment, four thermistors 81 (1) to 81 (4) are connected to the cell group 1
2 is inserted in series between the positive side terminal 12p and the voltage detection line W +, and each is arranged in the vicinity of each of the unit cells 11 (C1) to 11 (C4). The means, the temperature comparing means, and the voltage output means are commonly configured, and the configuration can be greatly simplified.

(Twelfth Embodiment) FIGS. 19 and 20 show a twelfth embodiment of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. Only the parts will be described. As shown in FIG.
In the abnormality detection device 13a of the embodiment, the switch 38 is removed from the abnormality detection device 13 of the first embodiment, and the AND gate 2
9 is output directly to the outside. That is, the AND gate 29 has a configuration also serving as voltage output means.

As shown in FIG. 20, the signal SC output from each abnormality detector 13a is given to a voltage detector 82 provided for each abnormality detector 13a. The output signal of 82 is given to the input port of the CPU 17 via the multiplexer 83 and the A / D converter 90. Note that the voltage detector 82 is required because the ground level of each abnormality detection device 13a is different from the ground level of the control unit 84.
This is because the level of the output signal SC cannot be directly referred to.

Next, the operation of the twelfth embodiment will be described. As in the first embodiment, the output signal SC of the AND gate 29 is "H" when the cell group 12 is normal and "L" when an abnormality occurs in the cell group 12. Accordingly, the CPU 17 sequentially switches the input of the multiplexer 83 and outputs the output signal S from each abnormality detection device 13a.
By referring to the level of C, any cell group 12
Can be determined whether an abnormality has occurred.

As described above, according to the twelfth embodiment, by using a signal line independent of the voltage detection lines W + and W-, even if an abnormality occurs in the cell group 12, the CPU 17 12 can be constantly detected by the voltage detector 14, and the reliability can be improved.

In the twelfth embodiment, the voltage detector 82 for detecting the level of the output signal SC is "H",
Since it is only necessary to be able to determine “L”, it is possible to use a low-accuracy one with low accuracy. For example, in place of the voltage detector 82, a level conversion circuit for converting the level of the output signal SC into the "H (for example, 5V)" or "L (0V)" level of the CPU 17 may be provided. / D
The converter 90 becomes unnecessary. Further, instead of the voltage detector 82, an element that electrically insulates between the input and the output, such as a photocoupler, may be used. The output level of the AND gate 29 may be inverted to output “H” when an abnormality is detected.

(Thirteenth Embodiment) FIGS. 21 and 22 show a thirteenth embodiment of the present invention. The same parts as those in the first and fourth embodiments are denoted by the same reference numerals and description thereof will be omitted. Hereinafter, only different portions will be described. As shown in FIG. 21, in the abnormality detection device 56a of the thirteenth embodiment, the output signal of the oscillation circuit 57 is controlled by a control terminal of a switch (voltage output means) 85 except for the switch 38 from the abnormality detection device 56 of the fourth embodiment. To give to. As shown in FIG. 22, the switch 85 has one end connected to a control power supply of the control unit 39A and the other end inserted into an abnormality detection line 86 connected to an input port of the CPU 17.

Next, the operation of the thirteenth embodiment will be described. When each cell group 12 is normal, since the output level of the AND gate 29 of each abnormality detection device 56a is "H" and the switch 85 is closed, the level of the input port of the CPU 17 becomes the control power supply level. "H".

When an abnormality occurs in any of the cell groups 12, the output level of the AND gate 29 of the corresponding abnormality detection device 56a becomes "L", and the oscillation circuit 57
Outputs an oscillation signal, the switch 85 performs a switching operation according to the oscillation frequency. Therefore, C
Since the level of the input port of the PU 17 becomes “L” intermittently, the CPU 17 can determine the occurrence of the abnormality in the cell group 12 based on the level change.

In this case, if the oscillating frequency of the oscillating circuit 57 of each abnormality detecting device 56a corresponding to each cell group 12 is set to a different one, the CPU 17 detects the oscillating frequency to determine which cell group 12 Will also be able to know if an error has occurred.

As described above, according to the thirteenth embodiment, the first
As in the second embodiment, by using the signal line 86 independent of the voltage detection lines W + and W-, the CPU 17 detects the output voltage of the cell group 12 even if an abnormality occurs in the cell group 12. It can be always detected by the detector 14. When it is not necessary to know which cell group 12 has an abnormality, the oscillation circuit 57
Is omitted, and the switch 8 is output by the output signal of the AND gate 29.
5 may be separated.

The present invention is not limited to the embodiment described above and shown in the drawings, and the following modifications or extensions are possible. The number of unit cells connected in series per cell group is not limited to “4”. As the number of series connections increases, the total number of cell groups decreases, so the number of output voltage detections on the control unit side decreases.On the other hand, since the output voltage of the cell groups increases, components with a higher withstand voltage are used. Required. Therefore, the number of series connections may be appropriately set in consideration of a cost determined by a trade-off between the two. For example, assuming that the power supply is constituted by general-purpose electronic components which are not specifically designed to have a high withstand voltage specification, it is preferable to suppress the output voltage of the cell group to about 20V. Therefore, as in the above embodiment, the unit cell has a maximum voltage of 4.2.
In the case of a V lithium battery, 4-5 series is considered appropriate. Further, the number of cell groups connected in series is not limited to “20”, and may be appropriately set according to the output voltage required for the assembled battery.

For example, by combining the configuration of the second embodiment and the configuration of the fifth embodiment, the output voltage of the cell group 12 may be changed to a different level according to the type of abnormality that has occurred. Further, the output voltage may be changed at a different frequency depending on the position of the unit cell 11 in which the abnormality has occurred. Only one or two of the overdischarge detection circuit 30, the overcharge detection circuit 31, and the overheating detection circuit 37 may be provided. In the third embodiment, only one of the gas leak detection circuit 43 and the overcurrent detection circuit 44 may be provided. The unit cell is not limited to a lithium battery, and can be similarly applied to a lead battery or a nickel-based battery.

The voltage output means is not limited to the one capable of changing the terminal voltage VG of the cell group 12 as the output voltage, and the terminal voltage of at least one unit cell 11 constituting the cell group 12 is used as the output voltage. It may be something. The CPU 17 may perform only the abnormality determination function. In this case, for example, in the twelfth embodiment, the signal system of the voltage detector 14, the MPX 15, and the A / D converter 16 may be given to a separate CPU to perform an interface function for a control device such as an inverter. It is not limited to electric vehicles and HEVs, but is also constructed by connecting a plurality of unit cells in series, such as small consumer devices such as notebook personal computers and portable VTRs, and secondary battery facilities for power storage. Any battery that uses a battery can be applied.

[Brief description of the drawings]

FIG. 1 is a first embodiment in which the present invention is applied to a drive battery of a hybrid electric vehicle, and is a functional block diagram showing an electrical configuration of an entire voltage control unit.

FIG. 2 is a diagram showing a detailed electrical configuration of the abnormality detection device.

FIG. 3 is a diagram showing an example of a change in an output voltage of a cell group over time.

FIG. 4 is a view corresponding to FIG. 2, showing a second embodiment of the present invention;

FIG. 5 is a diagram corresponding to FIG. 3;

FIG. 6 is a view corresponding to FIG. 2 of a main part showing a third embodiment of the present invention.

FIG. 7 is a view corresponding to FIG. 6, showing a fourth embodiment of the present invention;

FIG. 8 is a diagram corresponding to FIG. 3;

FIG. 9 is a view corresponding to FIG. 6, showing a fifth embodiment of the present invention.

FIG. 10 is a diagram corresponding to FIG. 3;

FIG. 11 is a view corresponding to FIG. 2, showing a sixth embodiment of the present invention;

FIG. 12 is a diagram showing a detailed electrical configuration of a voltage adjustment circuit.

FIG. 13 is a diagram corresponding to FIG. 1;

FIG. 14 shows the seventh embodiment of the present invention, and is a perspective view showing the outer shape of a cell group.

FIG. 15 is a view corresponding to FIG. 14 showing an eighth embodiment of the present invention.

FIG. 16 is a view corresponding to FIG. 14, showing a ninth embodiment of the present invention;

FIG. 17A is a diagram showing a tenth embodiment of the present invention.
4, (b) is a front view of a cell holder, and (c) is a plan view of a cell group.

FIG. 18 is a view corresponding to FIG. 2, showing an eleventh embodiment of the present invention;

FIG. 19 is a view corresponding to FIG. 2, showing a twelfth embodiment of the present invention;

FIG. 20 is a view corresponding to FIG. 1;

FIG. 21 is a view corresponding to FIG. 2 showing a thirteenth embodiment of the present invention.

FIG. 22 is a diagram corresponding to FIG. 1;

FIG. 23 is a diagram showing a conventional technique, which is equivalent to FIG. 1;

[Explanation of symbols]

11, 11A are unit cells (lithium batteries), 12, 12
A is a cell group, 13 and 13a are abnormality detection devices, 14
Is a voltage detector (voltage detecting means), and 17 and 17a are CPUs.
(Abnormality determining means, voltage control means), 19 is an assembled battery (driving battery), 29 is an AND gate (abnormality detecting means, voltage output means), 30 is a lower limit voltage detecting circuit (abnormality detecting means, lower limit voltage comparing means) , 31 are an upper limit voltage detecting circuit (abnormality detecting means, upper limit voltage comparing means), 34 is a thermistor (temperature detecting means), 37 is an overheating detecting circuit (abnormality detecting means, temperature comparing means), and 38 is a switch (voltage output means). means,
Current interrupting means), 39 and 39A are control units, and 40 is AND
Gates (abnormality detecting means), 41 and 42 are abnormality detecting devices,
43 is a gas leak detecting circuit (abnormality detecting means, gas concentration comparing means), 44 is an overcurrent detecting circuit (abnormality detecting means, overcurrent detecting means), 47 is a gas sensor (gas concentration detecting means),
50 is an AND gate (abnormality detection means), 52 is a shunt resistor (output current detection means), 56 and 56a are abnormality detection devices, 57 is an oscillation circuit (voltage output means), 58 is an abnormality detection device, and 59 is an AND gate ( Abnormality detection means), 60 is an oscillation circuit (voltage output means), 61 is an AND gate (abnormality detection means), 62 is an abnormality detection device, 63 is a voltage adjustment circuit (voltage adjustment means), 69 is a control unit, and 72 is a group. Intermediate voltage adjusting means, 74 is a terminal cover (parts), 77 is a module battery, 81 is a positive thermistor (abnormality detecting means, temperature detecting means, temperature comparing means, voltage output means), 8
Reference numeral 4 denotes a control unit, and reference numeral 85 denotes a switch (voltage output means).

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02J 7/02 H02J 7/02 HF term (Reference) 2G016 CA03 CB12 CB31 CC01 CC03 CC04 CC13 CC16 CC27 CC28 5G003 AA07 BA03 CA11 CB01 CB04 CC04 DA04 DA13 EA06 EA09 FA04 FA06 GC05 5H115 PG04 PI16 PI29 PU01 PU25 QN03 SE06 TI05 TI06 TI10 TR19 TU02 TU16 TU17

Claims (44)

[Claims] 1. An abnormality determination device for determining the occurrence of an abnormality during charging / discharging of an assembled battery formed by connecting a plurality of cell groups each formed by connecting a plurality of unit cells formed of a secondary battery in series. A plurality of abnormality detecting means for respectively detecting an abnormal state occurring in the plurality of cell groups; a plurality of voltage output means for changing an output voltage when the plurality of abnormality detecting means detects an abnormal state; A plurality of voltage detecting means for respectively detecting output voltages from the voltage output means, and when a change occurs in the output voltage detected by the plurality of voltage detecting means, abnormalities occur in the unit cells constituting the cell group. An abnormality determination device for an assembled battery, comprising: an abnormality determination unit configured to determine that an error has occurred. 2. The voltage output means according to claim 1, wherein a terminal voltage of at least one unit cell constituting a corresponding cell group is changeable as its own output voltage. Battery battery abnormality determination device. 3. The battery pack abnormality determination device according to claim 2, wherein said voltage detection means is configured to be able to change a terminal voltage of a corresponding cell group as its own output voltage. 4. The abnormal condition detecting means includes a lower-limit voltage comparing means for comparing a terminal voltage of each unit cell constituting the cell group with a lower-limit voltage, and a terminal voltage of any one of the unit cells is lower than the lower-limit voltage. 4. The apparatus according to claim 1, wherein an abnormality is detected when the abnormality is detected. 5. The abnormal condition detecting means includes an upper limit voltage comparing means for comparing a terminal voltage of each unit cell constituting the cell group with an upper limit voltage, wherein a terminal voltage of any one of the unit cells rises above the upper limit voltage. The abnormality determination device for an assembled battery according to any one of claims 1 to 4, wherein an abnormality is detected when the abnormality is detected. 6. The temperature detecting means for detecting at least one temperature of each of the unit cells constituting the cell group, and a temperature comparing means for comparing the temperature detected by the temperature detecting means with a reference temperature. The abnormality determination device for an assembled battery according to any one of claims 1 to 5, further comprising means for detecting an abnormality when the temperature detected by the temperature detection means exceeds the reference temperature. 7. The temperature detecting means is constituted by the same number of positive thermistors as the number of unit cells constituting a cell group, wherein each of the positive thermistors comprises a positive terminal of the cell group and a positive voltage of the cell group. 7. The abnormality determination device for a battery pack according to claim 6, wherein the device is disposed in the vicinity of each unit cell by being interposed in series with the detection line. 8. A gas concentration detecting means for detecting a concentration of gas leaking from a unit cell in a cell group, and a concentration for comparing the gas concentration detected by the gas concentration detecting means with a reference concentration. 8. The abnormality of the battery pack according to claim 1, further comprising a comparison unit, wherein the abnormality is detected when the gas concentration detected by the gas concentration detection unit exceeds the reference concentration. Judgment device. 9. The battery pack abnormality judging device according to claim 1, wherein said voltage output means sets the output voltage to 0 V when said abnormality detection means detects an abnormal state. . 10. The battery pack according to claim 1, wherein said voltage output means periodically changes the output voltage when said abnormality detection means detects an abnormal state. Judgment device. 11. The battery pack abnormality judging device according to claim 10, wherein said voltage output means changes a fluctuation cycle of the output voltage in accordance with a type of an abnormal state detected by said abnormality detection means. . 12. The abnormality detecting means is configured to output a detection output of an abnormal state for each unit cell in a corresponding cell group, and the voltage output means is configured to output the abnormal state by the abnormality detecting means. The battery pack abnormality determination device according to claim 10, wherein the fluctuation period of the output voltage is changed in accordance with the position of the unit cell in which is detected. 13. The battery pack according to claim 1, wherein said voltage output means changes an output voltage in accordance with a type of an abnormal state detected by said abnormality detection means. Judgment device. 14. The abnormality detection means is configured to output a detection output of an abnormal state for each unit cell in a corresponding cell group, and the voltage output means is configured to output an abnormal state by the abnormality detection means. 9. The apparatus according to claim 1, wherein the output voltage is changed in accordance with the position of the unit cell in which the voltage is detected. 15. The voltage output means, when the abnormality detection means detects an abnormal state, outputs the output voltage of the cell group in which the abnormal state is detected to the negative voltage of the unit cell in which abnormality is detected in the cell group. 9. The abnormality determination device for an assembled battery according to claim 3, wherein the abnormality is changed so as to be equal to the potential. 16. An abnormality detection device comprising the abnormality detection means and the voltage change detection means, wherein the abnormality detection device and the voltage detection means are connected by two wires. Items 1 to 1
5. The battery pack abnormality determination device according to any one of 5. 17. An output current detecting means for detecting a current flowing from a corresponding cell group to a voltage detecting means; a current value comparing means for comparing a current detected by the output current detecting means with a reference current value; 17. A device according to claim 1, further comprising: a current cutoff unit that cuts off a current flowing through the voltage detection unit when a current detected by the current detection unit exceeds the reference current value. An abnormality determination device for a battery pack as described in the above. 18. The battery pack abnormality determination device according to claim 1, wherein said abnormality detection means and said voltage change detection means obtain an operation power supply from a cell group. 19. The apparatus according to claim 19, wherein the abnormality detecting means and the voltage change detecting means are integrated with a unit cell constituting a cell group, a housing accommodating the cell group, or a component constituting the housing. The abnormality determination device for an assembled battery according to any one of claims 1 to 18. 20. A voltage adjusting means for adjusting a terminal voltage variation between unit cells constituting a cell group to be as small as possible, wherein the abnormality detecting means and the voltage change detecting means are provided with the voltage adjusting means and The abnormality determination device for a battery pack according to any one of claims 1 to 19, wherein the abnormality determination device is configured integrally. 21. The battery pack abnormality determination device according to claim 20, further comprising an inter-group voltage adjusting means for adjusting a variation in output voltage between each cell group as much as possible. 22. The apparatus according to claim 1, wherein the unit cell is a lithium battery. 23. The apparatus according to claim 22, wherein the lithium battery uses lithium nickel oxide as an active material for a positive electrode. 24. The abnormality determining apparatus for a battery pack according to claim 1, wherein the battery pack is used as a driving battery for an electric vehicle. 25. The apparatus according to claim 1, wherein the battery pack is used as a drive battery for a hybrid electric vehicle. 26. An abnormality judging method for judging the occurrence of an abnormality at the time of charging / discharging of an assembled battery formed by connecting a plurality of cell groups each formed by connecting a plurality of unit cells formed of a secondary battery in series. In the above, when the abnormality detecting means provided for each cell group detects an abnormal state occurring in the cell group, the corresponding voltage output means changes the output voltage, and the voltage output means changes the output voltage. Detecting the occurrence by the voltage detection means, it is determined that an abnormality has occurred in the unit cells constituting the cell group. 27. The battery pack according to claim 26, wherein said voltage output means changes a terminal voltage of at least one unit cell constituting a corresponding cell group as its own output voltage. Judgment method. 28. The method according to claim 27, wherein said voltage output means changes a terminal voltage of a corresponding cell group as its own output voltage. 29. The abnormality detecting means compares a terminal voltage of each unit cell constituting a cell group with a lower limit voltage,
3. An abnormality is detected when a terminal voltage of any one of the unit cells falls below the lower limit voltage.
29. The method for judging abnormality of a battery pack according to any one of items 6 to 28. 30. The abnormality detecting means compares a terminal voltage of each unit cell constituting a cell group with an upper limit voltage,
30. The battery pack abnormality determination method according to claim 26, wherein an abnormality is detected when a terminal voltage of any one of the unit cells rises above the upper limit voltage. 31. The abnormality detecting means compares at least one temperature of each unit cell forming a cell group with a reference temperature, and detects an abnormality when the temperature exceeds the reference temperature. Claims 26 to 3 characterized by the following:
0. The method of determining an abnormality of the battery pack according to any one of 0 to 0. 32. The abnormality detecting means compares the concentration of gas leaking from a unit cell in a cell group with a reference concentration, and detects an abnormality when the gas concentration exceeds the reference concentration. The method for determining abnormality of a battery pack according to any one of claims 26 to 31, wherein: 33. The battery pack abnormality determination method according to claim 26, wherein said voltage output means sets the output voltage to 0 V when said abnormality detection means detects an abnormal state. . 34. The abnormality of the battery pack according to claim 26, wherein said voltage output means periodically changes the output voltage when said abnormality detection means detects an abnormal state. Judgment method. 35. The method according to claim 34, wherein the voltage output means changes a fluctuation cycle of the output voltage according to a type of an abnormal state detected by the abnormality detection means. . 36. The abnormality detecting means outputs a detection output of an abnormal state for each unit cell in a corresponding cell group, and the voltage output means outputs a unit in which the abnormal state is detected by the abnormality detecting means. 35. The method according to claim 34, wherein the output voltage change cycle is changed according to the cell position. 37. The abnormality of the battery pack according to claim 26, wherein said voltage output means changes an output voltage according to a type of an abnormal state detected by said abnormality detection means. Judgment method. 38. The abnormality detecting means outputs a detection output of an abnormal state for each unit cell in a corresponding cell group, and the voltage output means outputs a unit in which the abnormal state is detected by the abnormality detecting means. 33. The method according to claim 26, wherein the output voltage is changed according to the position of the cell. 39. The voltage output means, when the abnormality detecting means detects an abnormal state, outputs the output voltage of the cell group in which the abnormal state is detected to the negative voltage of the unit cell in which abnormality is detected in the cell group. 33. The method according to claim 28, wherein the voltage is changed to be equal to the potential. 40. A current flowing from the corresponding cell group to the voltage detecting means is detected and compared with a reference current value, and when the current exceeds the reference current value, the current flowing to the voltage detecting means is cut off. The method for judging abnormality of a battery pack according to any one of claims 26 to 39, characterized in that: 41. The method according to claim 26, wherein the unit cell is a lithium battery. 42. The method according to claim 41, wherein the lithium battery uses lithium nickel oxide as an active material for a positive electrode. 43. The method according to claim 26, wherein the battery pack is used as a battery for driving an electric vehicle. 44. The method according to claim 26, wherein the battery pack is used as a drive battery for a hybrid electric vehicle.