JPH0883630A - Abnormality detecting device for battery set - Google Patents

Abstract

PURPOSE: To provide an abnormality detecting device for a battery set capable of detecting an abnormality when the battery set is not operated without wastefully consuming the power of the battery set. CONSTITUTION: A thermo-element 4 is heat-conductively coupled with a battery set 1. When an abnormality occurs on the battery set 1, i.e., when the internal short circuit of the battery 1 occurs and the temperature of the battery 1 abnormally rises, the electromotive force of the thermo-element 4 generated by the heat energy is utilized to operate a temperature monitor circuit 9. The occurrence of such temperature abnormality is stored in a memory means 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abnormality detecting device for an assembled battery in which a plurality of secondary batteries are connected in series or in series-parallel connection, and more particularly to a set of non-aqueous electrolyte secondary batteries such as lithium ion batteries. The present invention relates to an abnormality detection device suitable for batteries.

[0002]

2. Description of the Related Art In an electric vehicle or the like, an assembled battery is used in which a plurality of secondary batteries are connected in series or in series / parallel in a required capacity. As a conventional example of a device for detecting an abnormality of such an assembled battery, for example, Japanese Patent Laid-Open No. 1-2326
72 and JP-A-4-109823. These devices are equipped with a temperature sensor near the battery to detect the temperature of the battery during battery operation, that is, during charging or discharging, and issue an alarm when the temperature rises above a predetermined allowable temperature, or charging or discharging. Is to stop.

[0003]

However, all of the conventional abnormality detecting devices as described above detect the abnormality by detecting the temperature during the operation of the battery pack, that is, during charging or discharging. There is a problem in that it is not possible to detect an abnormality that occurs during non-operation, that is, when charging or discharging is not performed, such as an internal short circuit of a battery. Further, in an electric vehicle or the like, since the assembled battery generally serves as an energy source, in order to operate the conventional anomaly detection device even when the assembled battery is not operating, the anomaly detection device is powered by the assembled battery. Since it has to be driven, there is a problem that the electric power of the assembled battery is wasted.

The present invention has been made to solve the above-mentioned problems of the prior art, and detects an abnormality that occurs when the battery pack is not operating, without wasting the power of the battery pack. It is an object of the present invention to provide an assembled battery abnormality detecting device.

[0005]

In order to achieve the above object, the present invention is constructed as described in the claims. That is, in the invention according to claim 1, an assembled battery in which a plurality of cells each including one secondary battery or a module including a plurality of cells are connected in series or in series / parallel, and thermally conductive to the assembled battery. The thermoelectric element provided in contact with the assembled battery is operated by the electromotive force of the thermoelectric element generated by the heat generated when the assembled battery is not operating, that is, when the assembled battery is not charged or discharged, and A temperature monitor circuit that measures the temperature of the assembled battery and a storage unit that stores the abnormal temperature measured by the temperature monitor circuit are provided. The temperature may be measured by providing a temperature sensor in the temperature monitor circuit or by measuring the output of the thermoelectric element.

The invention described in claim 2 is the same as claim 1
In the configuration described in, when the assembled battery is operating, that is, at the time of charging or discharging, the stored content of the storage unit is read,
A determination means is added to notify the occurrence of an abnormality when an abnormal temperature rise is recorded. The above-mentioned determination means is incorporated in, for example, a control device (for example, a computer) or a charging device when driving a load with the electric power of the assembled battery, and operates when the load driving starts, that is, when the assembled battery starts discharging or charging. Then, it may be configured to determine the abnormality.

Further, in the invention according to claim 3, as the constitution of the judging means, the stored contents of the storing means are read out when the assembled battery is operating, that is, at the time of charging or discharging, and the cell or the module If the voltage value drops significantly and an abnormal temperature rise is recorded, it is judged as an internal short circuit in the battery, the voltage value of the above cell or module drops significantly, and an abnormal temperature rise is recorded. If not, it is configured to notify the battery by determining that the battery is self-discharged. In the invention according to claim 4, a temperature sensor for detecting the temperature of the thermoelectric element or the battery is provided for each of the cells or for each of the modules, and when an abnormality occurs in each of the cells or each of the modules. It is configured to measure and store the temperature.

Further, the invention according to claim 5 has one heat conduction mechanism provided in contact with all the cells or modules, and the thermoelectric element is provided in contact with the heat conduction mechanism. It is a thing. The heat conduction mechanism is, for example, a metal plate in contact with each cell or each module, and a thermoelectric element may be provided in contact with the metal plate.
Further, the secondary battery is, for example, a lithium ion secondary battery according to a sixth aspect. However, the present invention can be applied to a battery pack of other secondary batteries such as other types of lithium secondary batteries and lead-acid secondary batteries.

[0009]

In the present invention, a thermoelectric element is provided in thermal contact with the assembled battery, and when the assembled battery is abnormal, that is, when an internal short circuit of the battery occurs and the temperature of the battery abnormally rises, the heat The electromotive force of the thermoelectric element generated by the energy is used to operate the temperature monitor circuit, and the storage means stores the occurrence of such a temperature abnormality. According to the above configuration, the fact that the abnormality has occurred can be surely stored even when the assembled battery is not operating, that is, when the battery is not being charged or discharged, and the temperature monitor circuit is driven. Since the electric power of the battery pack is not used at all as an energy source for energy consumption, no unnecessary electric power is consumed.

Further, the abnormality information stored in the storage means is provided with the determination means as described in claim 2, and the abnormality information stored in the storage means is stored in the storage means at the time of operating the battery pack, that is, at the time of charging or discharging, particularly at the start thereof. By reading the stored contents and notifying the occurrence of an abnormality when an abnormal rise in temperature is recorded,
An operator can be notified of the occurrence of an abnormality. Further, the notification signal can be used to stop charging and discharging. Further, as described in claim 3, it is possible to distinguish between the internal short circuit and the self-discharge. That is, in the case of an internal short circuit and self-discharge, the voltage will both decrease,
The voltage cannot be used to make the distinction. But,
In the case of simple self-discharge, there is no abnormal temperature rise, so
It is possible to read the stored contents of the storage means and determine that there is an internal short circuit if there is a record of an abnormal temperature rise and the voltage drops (eg, drops to 0 V), and self-discharge if only the voltage drops. I can.

Further, as described in claim 4, by providing a thermoelectric element or a temperature sensor for each cell or each module, the temperature at the time of abnormality is measured and stored for each cell or each module. That is, it is possible to detect which cell or module has an abnormality. Further, as described in claim 5, if one heat conduction mechanism provided in contact with all cells or modules, for example, a metal plate is provided and the thermoelectric element is provided in contact with the metal plate, one Thermoelectric elements can be used to harness the heat generated by all cells or modules. In this case, if the battery pack as a whole can detect whether or not an abnormality has occurred, it can be configured with only one thermoelectric element, but which of the cells or modules has an abnormality? In order to store the above, it is necessary to provide a separate temperature sensor for each cell or each module.
Further, the present invention can be applied to an assembled battery composed of all types of secondary batteries, but as described in claim 6, it is particularly suitable for a battery such as a lithium-ion secondary battery that has a great need to reliably detect an abnormality. Is suitable.

[0012]

EXAMPLES The present invention will be described in detail below based on examples. FIG. 1 is a diagram of a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an assembled battery, in which batteries 1a to 1n (cells formed of a single battery or a module formed of a plurality of cells) are connected in series. It should be noted that they may be connected in series and parallel. 2 is a control device,
The electric power supply is controlled when the load 3 is driven by the electric power of the assembled battery 1. For example, the control device 2 is a circuit including a DC / AC converter and a control computer in an electric vehicle, and the load 3 is an electric vehicle driving motor. Reference numeral 4 denotes a thermoelectric element, which produces an electromotive force corresponding to the thermoelectric element, and is provided in contact with each battery. Reference numeral 5 is a capacitor for storing electricity, 6 is a resistor, 7 is a Zener diode, 8 is a transistor, 9 is a temperature monitor circuit, 10 is a memory device, and 11 is an arithmetic unit. The arithmetic unit 11 can share the control computer of the control unit 2, for example. A charging device (not shown) may be connected to the assembled battery 1 instead of the control device 2 and the load 3. Further, although only one thermoelectric element 4 is shown, it may be provided for each battery. Alternatively, one battery may be provided for the entire assembled battery 1. However, in that case, a heat conduction mechanism (for example, a metal plate) that is in thermal contact with all the batteries of the assembled battery is provided, and the thermoelectric element 4 is attached to the metal plate. By doing so, even if any battery generates abnormal heat, the heat can be effectively used.

Next, the operation will be described. When the assembled battery 1 is not operating, that is, when neither charging nor discharging is performed, the control device 2 and the arithmetic device 11 are not operating, and therefore, power is not consumed. In this state, for example, when an internal short circuit occurs in the battery 1a in the assembled battery 1, the temperature of the battery 1a rises and the heat causes the thermoelectric element 4 to output electric power. The electric power is stored in the capacitor 5. When the terminal voltage of the capacitor 5 rises and exceeds the Zener voltage of the Zener diode, a base current flows through the transistor 8 through the resistor 6 and the Zener diode 7, and the transistor 8 is turned on. Therefore, the electric power of the thermoelectric element 4 is given to the temperature monitor circuit 9, and the temperature monitor circuit 9 operates. The temperature monitor circuit 9 uses the battery 1a based on the output voltage of the thermoelectric element 4.
Of temperature is determined and the value is written in the memory device 10.
It should be noted that the temperature monitor circuit 9 determines the temperature and uses the memory device 10.
As long as it is a circuit having a writing function to the thermoelectric element 4, it can sufficiently operate with the electromotive force of the thermoelectric element 4. As described above, when the assembled battery 1 is abnormal and heat is generated when the assembled battery 1 is not operating, the temperature can be stored in the memory device 10. In this case, since the electric power for operating each circuit is entirely due to the electromotive force of the thermoelectric element 4, the electric power of the battery pack 1 is not consumed at all.

Next, when the battery pack is in operation, for example, the control device 2
When the load 3 is driven via the control unit 2, electric power from the battery pack 1 is applied to the control device 2 and the arithmetic device 11 (for example, a part of the control device 2), and those devices are activated. that time,
If the memory device 10 reads the stored contents of the memory device 10 and the temperature rise is recorded, it is possible to detect that an abnormality has occurred. The detection result can be displayed to an operator or the like by a display device or the like (not shown), or the detection result can be sent to the control device 2 and controlled so as to stop discharging or charging the battery pack 1. it can.

As mentioned above, in the embodiment of FIG.
It operates only when an abnormality occurs in the assembled battery 1, and the abnormality occurrence can be stored by utilizing the energy of abnormal heat generation. Therefore, without consuming the power of the assembled battery 1, it is possible to reliably detect the occurrence of an abnormality when the control device or the arithmetic device is not operating. In FIG. 1, only one thermoelectric element 4 and attached circuits (portions 5 to 8) are shown, but the thermoelectric element 4 and the circuit are provided for each battery, and the temperature monitor circuit 9 generates heat. If the batteries are distinguished and stored in the memory circuit 10,
It is possible to distinguish and detect which battery has an abnormality.

Next, FIG. 2 is a second embodiment of the present invention. In FIG. 2, reference numeral 12 is a voltage sensor for detecting the voltage of each battery of the assembled battery 1, and the same reference numerals as those in FIG. 1 denote the same components. The apparatus shown in FIG.
When is activated, depending on the stored content of the memory device 10 and the voltage of the cell or module obtained by the voltage sensor 12,
It is to judge whether it is an internal short circuit or a simple self-discharge. That is, if the voltage value of the battery has dropped significantly and an abnormal rise in temperature has been recorded, it is an internal short circuit of the battery,
If the voltage value is significantly reduced but no abnormal temperature rise is recorded, it can be determined that the discharge is just self-discharge. The voltage sensor 12 may simply be a connection from each battery to the arithmetic unit 11, and the D / A in the arithmetic unit 11 may be connected.
The voltage value may be determined by a converter or the like. In FIG. 2, the voltage sensor 12 is omitted and only one is shown, but this is provided for each battery. Other functions and effects are the same as those in FIG.

Next, FIG. 3 is a diagram showing a third embodiment of the present invention. In FIG. 3, 13 is a temperature sensor for detecting the temperature of the battery, 14 is a transistor, 15 to 17 are resistors, and the same reference numerals as those in FIG. 1 indicate the same things. Next, the operation will be described. When an internal short circuit occurs in the battery 1a in the assembled battery 1 when the assembled battery 1 is not operating, the temperature of the battery 1a rises and the heat causes the thermoelectric element 4 to output electric power. The electric power is stored in the capacitor 5. When the terminal voltage of the capacitor 5 rises and exceeds the Zener voltage of the Zener diode, a base current flows through the transistor 8 through the resistor 6 and the Zener diode 7, and the transistor 8 is turned on. Therefore, the base current also flows through the transistor 14 and the transistor 14 becomes conductive, so that the base current of the transistor 8 bypasses the Zener diode 7 and flows through the transistor 14. Therefore, once the transistors 8 and 14 are turned on, the transistor 8 continues to be turned on and the temperature monitor circuit 9 can continue to operate even if the voltage of the thermoelectric element 4 or the capacitor 5 is lowered to some extent. By thus providing the hysteresis characteristic, stable abnormality detection can be performed.

Further, in the circuit of FIG. 3, the thermoelectric element 4
A temperature sensor 13 is provided separately from the temperature sensor 13. The temperature monitor circuit 9 detects the temperature of the battery based on the signal from the temperature sensor 13. With this configuration, the battery temperature can be detected more accurately. Further, if the temperature sensor 13 is attached to each battery, only one thermoelectric element 4 and its circuit need be provided in the entire assembled battery 1. However, in that case, as described above, a metal plate that is in thermal contact with all the batteries of the assembled battery is provided, and the thermoelectric element 4 is attached to the metal plate. This makes it possible to effectively utilize the heat generated in any battery, and to store the battery in which a temperature sensor is provided for each battery. I can. The configuration in which the temperature sensor 13 is provided separately from the thermoelectric element 4 can naturally be applied to FIGS. 1 and 2 described above. Also,
The voltage sensor 12 of FIG. 2 is provided in the configuration of FIG.
It is also possible to provide a determination function similar to.

Next, FIG. 4 is a diagram showing a fourth embodiment of the present invention. In this embodiment, a backup battery 18 is provided so that the temperature monitor circuit operates reliably even when the output of the thermoelectric element 4 is relatively low. In FIG. 4, 18 is a backup battery, 19 to 21 are diodes, 22 and 23 are resistors, and the same reference numerals as those in FIG. 3 indicate the same things. Although the circuit of FIG. 4 shows the case where the thermoelectric element 4 and the temperature sensor 12 are provided in contact with the battery 1a in the assembled battery 1, the thermoelectric element 4 and its circuit (backup battery 18 May be provided for each battery, or only one may be provided for the entire assembled battery 1 via a metal plate for heat transfer. If one is provided for the whole,
The negative side terminal of the backup battery 18 is connected to the negative side terminal of the entire assembled battery 1 (the negative terminal of the battery 1n). Further, the temperature sensor 13 is provided for each battery. When the output voltage of the thermoelectric element 4 rises due to abnormal heat generation of the battery and exceeds the Zener voltage of the Zener diode 7, the transistor 8 becomes conductive. Therefore, the power of the backup battery 18 is supplied to the temperature monitor circuit 9, and the temperature monitor circuit 9 operates. In this case, since the electromotive force of the thermoelectric element 4 only needs to make the transistor 8 conductive, the temperature can be reliably detected even when the temperature of abnormal heat generation is relatively low. Further, since the electromotive force of the thermoelectric element 4 is also provided as the electric power of the temperature monitor circuit 9 via the resistor 22 and the diode 21, the temperature rises and the electromotive force of the thermoelectric element 4 increases. If it does, that power can also be used. Therefore, even if the backup battery 18 is self-discharged, it can be reliably detected if an abnormal temperature occurs. The backup battery 1
8 is simultaneously charged via the diode 19 when the assembled battery 1 is charged. In addition, the configuration of FIG.
It is also possible to provide the voltage sensor 12 and to provide the same determination function as in FIG.

Next, FIG. 5 is a fifth embodiment of the present invention. In this embodiment, the temperature sensor 13 is omitted from the embodiment of FIG. 4, and the temperature is detected by the output of the thermoelectric element 4. In FIG. 5, both terminals of the thermoelectric element 4 are connected to the temperature monitor circuit 9, and the temperature signal of the thermoelectric element 4 is sent to the temperature monitor circuit 9. Other configurations and operations are similar to those of the circuit of FIG.

[0021]

As described above, in the present invention, a thermoelectric element is provided in contact with the assembled battery in a heat conductive manner, and the electromotive force of the thermoelectric element generated by the thermal energy generated when the assembled battery is abnormal is utilized. By activating the temperature monitor circuit and storing the occurrence of such a temperature abnormality in the storage means, the fact that the abnormality occurred can be reliably stored even when the battery pack is not operating. Since the electric power of the assembled battery is not used at all as an energy source for driving the temperature monitor circuit, there is no waste of electric power. Further, in the invention according to claim 2, when the battery pack is in operation, the stored contents of the storage means are read out, and when an abnormal rise in temperature is recorded, the occurrence of an abnormality is informed, so that an operator or the like has an abnormality. It is possible to announce the occurrence. Further, the notification signal can be used to stop charging and discharging. Further, in the invention according to claim 3, it is possible to distinguish between the internal short circuit and the self-discharge. Further, in the invention according to claim 4, it is possible to detect which cell or module has an abnormality. Further, in the invention described in claim 5, many effects can be obtained such that the heat generation of all cells or modules can be utilized by using one thermoelectric element. Although the present invention can be applied to an assembled battery composed of all types of secondary batteries, as described in claim 6, it is particularly applicable to a battery such as a lithium-ion secondary battery that has a large need to reliably detect an abnormality. Is suitable.

[Brief description of drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention.

FIG. 2 is a block diagram of a second embodiment of the present invention.

FIG. 3 is a block diagram of a third embodiment of the present invention.

FIG. 4 is a block diagram of a fourth embodiment of the present invention.

FIG. 5 is a block diagram of a fifth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Assembly battery 10 ... Memory 1a-1n ... Battery (cell or module) 11 ... Arithmetic device 2 ... Control device 12 ... Voltage sensor 3 ... Load 13 ... Temperature sensor 4 ... Thermoelectric element 14 ... Transistor 5 ... Capacitor 15-17 ... Resistor 6 ... Resistor 18 ... Backup battery 7 ... Zener diode 19-21 ... Diode 8 ... Transistor 22, 23 ... Resistor 9 ... Temperature monitor circuit

Claims (6)

[Claims] 1. A battery pack in which a plurality of cells each composed of one secondary battery or a module consisting of a plurality of cells are connected in series or in series and parallel, and a thermoelectric element provided in thermal conductive contact with the battery pack. And when the assembled battery is not operating, that is, when charging and discharging are not performed, the assembled battery is operated by the electromotive force of the thermoelectric element generated by the heat generated when the assembled battery is abnormal, and the temperature of the assembled battery is measured. An abnormality detecting device for an assembled battery, comprising: a temperature monitor circuit; and storage means for storing the temperature at the time of abnormality measured by the temperature monitor circuit. 2. When the assembled battery is in operation, that is, at the time of charging or discharging, the storage contents of the storage means are read out, and a determination means is provided to notify the occurrence of an abnormality when an abnormal rise in temperature is recorded. The assembled battery abnormality detection device according to claim 1. 3. The determination means reads the stored contents of the storage means at the time of operating the assembled battery, that is, at the time of charging or discharging, so that the voltage value of the cell or module is significantly lowered, and If an abnormal rise is recorded, it is judged as an internal short circuit of the battery, and if the voltage value of the cell or module has dropped significantly and no abnormal rise in temperature has been recorded, the battery self-discharges. The abnormality detecting device for an assembled battery according to claim 2, wherein the abnormality detecting device is configured to make a determination and notify. 4. A temperature sensor for detecting the temperature of the thermoelectric element or the battery is provided for each cell or each module, and an abnormal temperature is measured and stored for each cell or each module. The assembled battery abnormality detecting device according to any one of claims 1 to 3, wherein 5. A heat conduction mechanism provided in contact with all cells or modules, wherein the thermoelectric element is provided in contact with the heat conduction mechanism. An abnormality detection device for an assembled battery according to any one of 1. 6. The assembled battery abnormality detection device according to claim 1, wherein the secondary battery is a lithium ion secondary battery.