JP6955673B2 - Battery abnormality detection system - Google Patents

Description

The present invention relates to a battery abnormality detection system.

A battery such as a lithium ion secondary battery is generally used as a battery stack including a plurality of batteries or a battery pack in which a plurality of the battery stacks are combined. Here, if the temperature of each battery varies in the same stack, the battery performance may vary between the batteries. If the battery performance varies, the possibility of overcharging in each battery increases. Here, as a technique for detecting a temperature change of a battery, for example, Patent Document 1 discloses a technique for utilizing cooling air flowing toward the battery during high-load traveling. Further, Patent Document 2 and Patent Document 3 are mentioned as control techniques based on the temperature of the battery.

Japanese Unexamined Patent Publication No. 2015-129677 Japanese Unexamined Patent Publication No. 2016-167420 Japanese Unexamined Patent Publication No. 2012-029491

By the way, in the technique described in Patent Document 1, the cooling air flows only during high-load traveling and does not flow during normal traveling. In addition, the cooling air does not flow even during parking, which is the most frequently used form in the market, and changes in battery temperature cannot be detected. That is, it is not possible to detect an abnormality in the battery while parking.

The present invention has been made in view of such a point, and an object of the present invention is to provide a battery abnormality detection system capable of detecting a battery abnormality while parking.

The battery abnormality detection system according to the present invention is mounted on a vehicle including a vehicle driving battery. The battery abnormality detection system includes a first temperature detection device that measures the temperature Tx0 of the vehicle drive battery at the end of traveling and the temperature Tx1 of the vehicle drive battery when a predetermined time has elapsed from the end of travel. It includes a second temperature detecting device for measuring the outside air temperature Ty0 of the vehicle at the end of traveling and the outside air temperature Ty1 of the vehicle when the predetermined time has elapsed from the end of traveling, and a control device. The control device is associated with the outside temperature Ty2 of the vehicle at the end of travel, the temperature Tx2 of the vehicle driving battery at the end of travel, and the outside temperature of the vehicle when the predetermined time has elapsed from the end of travel. A plurality of assumed conformance coefficients α1 which are ratios {Tx3 / (Tx2-Ty3)} of the temperature Tx3 of the vehicle driving battery when the predetermined time elapses from the end of traveling with respect to the difference (Tx2-Ty3) from Ty3. A plurality of storage units stored in the storage unit based on the storage unit, the temperature Tx0 measured by the first temperature detection device, and the outside temperature Ty0 measured by the second temperature detection device. A selection unit that selects one assumed conformity coefficient α1 from the assumed conformity coefficient α1, the temperature Tx0 and the temperature Tx1 measured by the first temperature detection device, and the said temperature Tx1 measured by the second temperature detection device. A calculation unit that calculates the actual measurement conformity coefficient α2, which is the ratio {Tx1 / (Tx0-Ty1)} of the temperature Tx1 to the difference (Tx0-Ty1) between the temperature Tx0 and the outside temperature Ty1 based on the outside temperature Ty1. When the assumed conformity coefficient α1 selected by the selection unit is larger than the actually measured conformity coefficient α2, it is determined to be abnormal, and when the assumed conformity coefficient α1 is equal to or less than the actually measured conformity coefficient α2, it is determined to be normal. It is equipped with a determination unit.

According to the battery abnormality detection system according to the present invention, the assumed conformity calculated based on the battery temperature and the outside air temperature of the vehicle at the end of running in the normal state measured in advance and when a predetermined time has passed from the end of running. By comparing the coefficient α1 with the actually measured conformity coefficient α2 calculated based on the battery temperature and the outside air temperature of the vehicle when a predetermined time has passed since the end of the run and the end of the run. It is possible to determine an abnormality in the vehicle drive battery. That is, the determination unit determines that it is abnormal when the assumed conformity coefficient α1 is larger than the actually measured conformity coefficient α2, and determines that it is normal when the assumed conformity coefficient α1 is equal to or less than the actually measured conformity coefficient α2. In this way, even when the vehicle is parked, it is possible to accurately detect whether or not an abnormality has occurred in the vehicle driving battery. In addition, since it is possible to detect the presence or absence of an abnormality in the vehicle drive battery when the vehicle drive battery is not used, it is more excellent in safety.

It is a top view which shows typically the battery abnormality detection system mounted on a vehicle. It is a flowchart which shows the procedure for confirming the state of the vehicle driving battery after parking. It is a graph which shows the temperature change after parking of a vehicle driving battery.

Hereinafter, preferred embodiments of the present invention will be described. Matters other than those specifically mentioned in the present specification and necessary for carrying out the present invention can be grasped as design matters of those skilled in the art based on the prior art in the art. The present invention can be carried out based on the contents disclosed in the present specification and common general technical knowledge in the art. It should be noted that each drawing is drawn schematically and does not necessarily reflect the actual product. In addition, each drawing shows only one example, and each drawing does not limit the present invention unless otherwise specified. Further, the symbols F, Rr, L, and R in the drawing mean front, back, left, and right, respectively. However, these are directions for convenience of explanation, and do not limit the installation mode of the battery abnormality detection system at all.

As shown in FIG. 1, the vehicle 10 includes a battery pack 20 and a battery abnormality detection system 30. In the present embodiment, the battery pack 20 is arranged under the rear seat of the vehicle 10 and fixed to the floor panel. However, the battery pack 20 may be arranged on a position other than the lower side of the rear seat.

The battery pack 20 includes a battery stack 22 and a case 23. The battery stack 22 includes four vehicle driving batteries 21. Each of the four vehicle driving batteries 21 has a square outer shape, and is arranged in a row in the left-right direction of FIG. 1 so that a pair of flat surfaces face each other. The four vehicle drive batteries 21 are electrically connected to each other in series by a bus bar. The four vehicle drive batteries 21 are integrally held by a restraint band or the like. However, the shape, number, arrangement, etc. of the vehicle drive battery 21 may be changed as appropriate. The vehicle drive battery 21 is typically a rechargeable / dischargeable secondary battery, such as a lithium ion secondary battery. The vehicle drive battery 21 typically includes a positive electrode, a negative electrode, an electrolytic solution, and a cell cell case for accommodating them. The electrolytic solution contains, for example, a non-aqueous solvent such as carbonates and a supporting salt such as a lithium salt. The configuration of the cell is the same as the conventional one, and is not particularly limited.

The case 23 is a housing for accommodating the battery stack 22. The material of the case 23 is, for example, metal or resin. The shape and size of the case 23 may be appropriately changed according to, for example, the size and number of battery stacks 22.

As shown in FIG. 1, the battery abnormality detection system 30 includes a first temperature detection device 31, a second temperature detection device 32, and a control device 35.

The first temperature detection device 31 is a device that measures the temperature of the vehicle drive battery 21. Examples of the first temperature detection device 31 include a thermocouple. The first temperature detection device 31 is provided in each vehicle driving battery 21. The first temperature detecting device 31 is attached to, for example, the cell cell case of the vehicle driving battery 21. The first temperature detection device 31 is electrically connected to the control device 35. The temperature information measured by the first temperature detection device 31 is transmitted to the control device 35.

The first temperature detecting device 31 measures the temperature Tx0 of the vehicle driving battery 21 at the end of traveling. The first temperature detection device 31 measures the temperature Tx1 of the vehicle drive battery 21 when a predetermined time t has elapsed from the end of traveling (that is, when a predetermined time t has elapsed after parking). The predetermined time t can be arbitrarily set, for example, 10 minutes, 30 minutes, 1 hour, or the like.

The second temperature detection device 32 is a device that measures the outside air temperature of the vehicle 10. Examples of the second temperature detection device 32 include a thermistor. The second temperature detection device 32 is provided, for example, on the back side of the front bumper of the vehicle 10. The second temperature detection device 32 is electrically connected to the control device 35. The temperature information measured by the second temperature detection device 32 is transmitted to the control device 35.

The second temperature detection device 32 measures the outside air temperature Ty0 of the vehicle 10 at the end of traveling. The second temperature detection device 32 measures the outside air temperature Ty1 of the vehicle when a predetermined time t has elapsed from the end of traveling (that is, when a predetermined time t has elapsed after parking).

The control device 35 includes a central processing unit (CPU) that executes instructions of a control program, a ROM that stores a program executed by the CPU, a RAM that is used as a working area for developing the program, and the above program and various data. It is equipped with a storage device such as a memory for storing the data. The control device 35 includes a storage unit 37, a selection unit 39, a calculation unit 41, a determination unit 43, and a notification unit 45. Each of these parts is realized by a program. This program can be downloaded via the internet. Further, each of these parts may be feasible by a processor and / or a circuit or the like. The specific control of each part described above will be described later.

The storage unit 37 stores a plurality of assumed conformity coefficients α1. The assumed conformity coefficient α1 is the difference (Tx2-Ty3) between the temperature Tx2 of the vehicle drive battery 21 at the end of running and the outside air temperature Ty3 of the vehicle 10 when a predetermined time t has elapsed from the end of running at the end of running. It is a ratio {Tx3 / (Tx2-Ty3)} of the temperature Tx3 of the vehicle driving battery 21 when a predetermined time t has elapsed from. The assumed conformity coefficient α1 is associated with the outside air temperature Ty2 of the vehicle at the end of traveling. That is, if the outside air temperature Ty2 and the temperature Tx2 are determined, the assumed conformity coefficient α1 is uniquely determined. The assumed conformity coefficient α1 is an assumed value obtained by a preliminary experiment.

The selection unit 39 has a plurality of assumed conformity coefficients α1 stored in the storage unit 37 based on the temperature Tx0 measured by the first temperature detection device 31 and the outside air temperature Ty0 measured by the second temperature detection device 32. Select one assumed fit coefficient α1 from. That is, the selection unit 39 uniquely selects the assumed conformity coefficient α1 by replacing the temperature Tx0 with the temperature Tx2 and replacing the outside air temperature Ty0 with the outside air temperature Ty2.

The calculation unit 41 determines the difference between the temperature Tx0 and the outside air temperature Ty1 based on the temperature Tx0 and the temperature Tx1 measured by the first temperature detection device 31 and the outside air temperature Ty1 measured by the second temperature detection device 32. The measured conformity coefficient α2, which is the ratio of the temperature Tx1 to Tx0-Ty1) {Tx1 / (Tx0-Ty1)}, is calculated. The actual measurement suitability coefficient α2 is an actual measurement value calculated based on the actually measured temperature and the outside air temperature.

When the assumed conformity coefficient α1 selected by the selection unit 39 is larger than the actually measured conformity coefficient α2 calculated by the calculation unit 41, the determination unit 43 determines that it is abnormal. The determination unit 43 determines that it is normal when the assumed conformity coefficient α1 selected by the selection unit 39 is equal to or less than the actually measured conformity coefficient α2 calculated by the calculation unit 41.

The notification unit 45 notifies the user of the abnormality of the vehicle driving battery 21. The notification method is not particularly limited, and examples thereof include visual display, voice notification, and the like. In the present embodiment, the operator is visually notified through a display panel (not shown) provided on the vehicle 10.

Next, a method of confirming the state of the vehicle driving battery 21 after parking will be described. FIG. 2 is a flowchart according to an embodiment. At the time of shipment of the vehicle 10, the assumed conformity coefficient α1 is stored in the storage unit 37. When the vehicle 10 is parked, the vehicle driving battery 21 is not charged or discharged.

First, when the traveling of the vehicle 10 is completed (that is, when the vehicle 10 is parked), in step S10, the first temperature detection device 31 measures the temperature Tx0 of the vehicle driving battery 21 at the end of traveling. Further, the second temperature detection device 32 measures the outside air temperature Ty0 of the vehicle 10 at the end of traveling.

Next, when the predetermined time t elapses, in step S20, the first temperature detection device 31 measures the temperature Tx1 of the vehicle driving battery 21 when the predetermined time t elapses from the end of traveling. Further, the second temperature detection device 32 measures the outside air temperature Ty1 of the vehicle 10 when a predetermined time t has elapsed from the end of traveling.

In step S30, the selection unit 39 selects one assumed fit coefficient α1 from the plurality of assumed fit coefficients α1 stored in the storage unit 37 based on the temperature Tx0 and the outside air temperature Ty0 measured in step S10.

In step S40, the calculation unit 41 calculates the measured conformity coefficient α2 based on the temperature Tx0 measured in step S10, the temperature Tx1 measured in step S20, and the outside air temperature Ty1.

In step S50, the determination unit 43 determines whether or not the assumed conformity coefficient α1 selected in step S30 is larger than the actually measured conformity coefficient α2. If it is determined that the assumed conformity coefficient α1 is larger than the actually measured conformity coefficient α2, the process proceeds to step S60. On the other hand, when the assumed conformity coefficient α1 is determined to be equal to or less than the actually measured conformity coefficient α2, the vehicle drive battery 21 is in a normal state, and the process ends.

In step S60, the notification unit 45 notifies the user of the abnormality of the vehicle drive battery 21 and ends the process.

FIG. 3 is a graph showing the temperature change of the vehicle driving battery 21 for 1 hour after parking. The solid line in FIG. 3 shows the temperature change when the assumed conformity coefficient α1 is equal to the actually measured conformity coefficient α2 (normal state). The broken line in FIG. 3 indicates the temperature change when the assumed conformity coefficient α1 is larger than the actually measured conformity coefficient α2 (abnormal state). As shown in FIG. 3, when the assumed conformity coefficient α1 is equal to the actually measured conformity coefficient α2, the temperature of the vehicle drive battery 21 is sufficiently lowered. On the other hand, when the assumed conformity coefficient α1 is larger than the actually measured conformity coefficient α2, the temperature of the vehicle driving battery 21 is not sufficiently lowered. As a result, it can be confirmed that heat cannot be sufficiently dissipated due to, for example, dust accumulating on the vehicle driving battery 21.

As described above, according to the battery abnormality detection system 30 according to the present embodiment, the abnormality of the vehicle drive battery 21 can be determined by comparing the assumed conformity coefficient α1 and the actually measured conformity coefficient α2. That is, the determination unit 43 determines that it is abnormal when the assumed conformity coefficient α1 is larger than the actually measured conformity coefficient α2, and determines that it is normal when the assumed conformity coefficient α1 is equal to or less than the actually measured conformity coefficient α2. In this way, even when the vehicle 10 is parked, it is possible to accurately detect whether or not an abnormality has occurred in the vehicle driving battery 21. Further, when the vehicle 10 is parked, the vehicle drive battery 21 is not charged or discharged, and it is possible to detect the presence or absence of an abnormality in the vehicle drive battery 21 when the vehicle drive battery 21 is not used. , Better in safety.

Although various battery abnormality detection systems proposed here have been described above, the embodiments and examples given here do not limit the present invention unless otherwise specified.

For example, in the above flowchart, the process of step S30 is performed after step S20, but step S30 may be processed before step S20.

10 Vehicle 21 Vehicle drive battery 30 Battery abnormality detection system 31 First temperature detection device 32 Second temperature detection device 35 Control device 37 Storage unit 39 Selection unit 41 Calculation unit 43 Judgment unit

Claims (1)

A battery abnormality detection system installed in a vehicle including a vehicle drive battery.
A first temperature detection device that measures the temperature Tx0 of the vehicle drive battery at the end of traveling and the temperature Tx1 of the vehicle drive battery when a predetermined time has elapsed from the end of travel.
A second temperature detecting device that measures the outside air temperature Ty0 of the vehicle at the end of traveling and the outside air temperature Ty1 of the vehicle when the predetermined time has elapsed from the end of traveling.
Equipped with a control device,
The control device is
The difference between the temperature Tx2 of the vehicle driving battery at the end of running and the outside air temperature Ty3 of the vehicle when the predetermined time elapses from the end of running, which is associated with the outside air temperature Ty2 of the vehicle at the end of running ( A storage unit that stores a plurality of assumed conformity coefficients α1 which are ratios {Tx3 / (Tx2-Ty3)} of the temperature Tx3 of the vehicle driving battery when the predetermined time elapses from the end of traveling with respect to Tx2-Ty3). When,
A plurality of assumed conformity coefficients α1 to 1 stored in the storage unit based on the temperature Tx0 measured by the first temperature detection device and the outside air temperature Ty0 measured by the second temperature detection device. A selection unit that selects the assumed conformity coefficient α1 and
The difference between the temperature Tx0 and the outside air temperature Ty1 based on the temperature Tx0 and the temperature Tx1 measured by the first temperature detection device and the outside air temperature Ty1 measured by the second temperature detection device ( A calculation unit that calculates the actual measurement conformity coefficient α2, which is the ratio of the temperature Tx1 to Tx0-Ty1) {Tx1 / (Tx0-Ty1)}.
If the assumed conformity coefficient α1 selected by the selection unit is larger than the actually measured conformity coefficient α2, it is determined to be abnormal, and if the assumed conformity coefficient α1 is equal to or less than the actually measured conformity coefficient α2, it is determined to be normal. And, equipped with a battery abnormality detection system.

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