JP7235553B2 - Automotive battery abnormality detection device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an abnormality detection device for an on-vehicle battery, and in particular, calculates an on-vehicle battery busbar resistance value and compares the busbar resistance value with a preset resistance threshold to detect an on-vehicle battery abnormality. The present invention relates to an anomaly detection device for an in-vehicle battery that detects with high accuracy.

Japanese Unexamined Patent Application Publication No. 2002-200002 discloses a conventional abnormality detection device for a power storage device. The power storage device is, for example, a lithium ion secondary battery or the like, and the positive electrode terminal and the negative electrode terminal of adjacent power storage devices are connected in series via a bus bar.

An abnormality detection device for a power storage device mainly includes an internal resistance detection section, an internal resistance determination section, and a contact resistance determination section. The internal resistance detection unit detects an internal resistance value of the power storage device while performing constant current discharging or constant current charging. Then, the internal resistance detection section outputs detection result information to the internal resistance determination section and the contact resistance determination section, respectively.

The internal resistance determination unit extracts, for example, an internal resistance value (10-second resistance value) from the detection result information, compares the internal resistance value with a preset threshold value, and determines whether the internal resistance of the power storage device is abnormal. Determine presence/absence.

The contact resistance determination unit determines whether there is an abnormality in contact resistance when the busbar is connected to the positive terminal and the negative terminal of the power storage device. Then, the contact resistance determination unit extracts, for example, an instantaneous resistance value (resistance value at 0.1 second) from the detection result information, compares the instantaneous resistance value with a preset threshold, and determines the contact resistance. Determine the presence or absence of anomalies.

Japanese Patent No. 6409389

The abnormality detection device for a power storage device disclosed in Patent Document 1 focuses on the correlation between the instantaneous resistance value of the internal resistance and the contact resistance value, in which the higher the instantaneous resistance value, the higher the contact resistance value. . By comparing the instantaneous resistance value and the threshold value, the step of inspecting the contact resistance is omitted, thereby simplifying the inspection process.

However, in recent years, in vehicles such as EVs (Electrical Vehicles), the amount of heat generated by the on-vehicle battery has increased as the capacity of the on-vehicle battery mounted on the vehicle has increased. Since the bus bar that electrically connects the battery modules of the vehicle battery has a higher thermal conductivity and a lower heat capacity than the battery, the bus bar reaches a high temperature immediately after the vehicle battery starts operating. As a result, due to the heat generated by the busbars, it is necessary to consider not only the fastening points of the busbars, but also the heat resistance characteristics of the busbars themselves, the fastening members, and the heat resistance characteristics of peripheral parts located near the busbars. There is a problem that it is difficult to control.

Furthermore, the heat generated by the busbars is transmitted to each battery module, and each battery module becomes a high temperature state, which may lead to a runaway mode. As mentioned above, due to the material characteristics of the busbar, the busbar heats up earlier than each battery module. expected to be very important in increasing

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. An object of the present invention is to provide an abnormality detection device for a vehicle-mounted battery that accurately detects a

In the vehicle battery abnormality detection device of the present invention, a plurality of battery modules are connected in series via a bus bar, and the vehicle battery abnormality detection device detects an abnormality in the vehicle battery. current measuring means for measuring a current flowing through the vehicle-mounted battery; voltage measuring means for measuring a voltage applied to the busbar between the battery modules; and a first current measured by the current measuring means. busbar resistance calculation means for calculating a first busbar resistance value of the busbar using the value and the first voltage value measured by the voltage measurement means; storage means for storing the resistance threshold value of the busbar; an abnormality determining means for comparing the first bus bar resistance value and the resistance threshold value to determine an abnormality of the on-vehicle battery; input/output limiting means for limiting input/output of the vehicle battery; The busbar resistance calculation means further calculates a second busbar resistance value using the second current value measured by the current measurement means and the second voltage value measured by the voltage measurement means. The abnormality determination means further compares the second busbar resistance value with the resistance threshold value to determine abnormality of the on-vehicle battery, and the notification means determines again the When it is determined that the vehicle battery is abnormal, the occupant is notified of the vehicle battery abnormality.

Further, in the on-vehicle battery abnormality detection device of the present invention, the resistance threshold in the storage means is at least a first conductor resistance threshold for determining the state of the bus bar or a value of a peripheral component disposed in the vicinity of the bus bar. It is characterized by storing a second conductor resistance threshold for judging the state.

Further, the vehicle-mounted battery abnormality detection apparatus of the present invention further includes vehicle state determination means for determining a state of the vehicle, wherein the vehicle state determination means determines that at least the vehicle is in a running state. In this case, the abnormality determining means determines that the on-vehicle battery is abnormal when the first busbar resistance value is greater than or equal to the first conductor resistance threshold value.

Further, in the vehicle-mounted battery abnormality detection device of the present invention, the abnormality determination means determines that the vehicle-mounted battery is abnormal when the second bus bar resistance value becomes equal to or greater than the second conductor resistance threshold value. It is characterized by judging.

Further, in the on-vehicle battery abnormality detection device of the present invention, the vehicle state determination means determines the state of the vehicle using at least the speed of the vehicle, the accelerator opening of the vehicle, or the first current value. characterized by

Further, the vehicle-mounted battery abnormality detection apparatus of the present invention further includes vehicle state determination means for determining the state of the vehicle, wherein the storage means determines at least the connection state of the bus bar as the resistance threshold value. When the vehicle state determination means determines that the vehicle is in a stopped state, the abnormality determination means determines that the first busbar resistance value is greater than or equal to the contact resistance threshold value. Thus, it is determined that the on-vehicle battery is abnormal.

Further, in the on-vehicle battery abnormality detection device of the present invention, the vehicle state determination means determines the state of the vehicle using at least the speed of the vehicle, the accelerator opening of the vehicle, or the first current value. characterized by

An abnormality detection device for a vehicle battery according to the present invention includes current measuring means for measuring current flowing through the vehicle battery, voltage measuring means for measuring voltage applied to a bus bar between battery modules, and current measuring means. busbar resistance calculation means for calculating a busbar resistance value of the busbar using the measured current value and the voltage value measured by the voltage measurement means; storage means for storing the resistance threshold value of the busbar; and the busbar resistance value and the resistance threshold value. and a notification means for notifying an occupant of the vehicle, wherein the notification means determines that the vehicle battery is abnormal by the abnormality determination means. In this case, the occupant is notified of the abnormality of the on-vehicle battery. With this structure, the occupants of the vehicle can immediately detect the abnormality of the vehicle battery through the notification means, and can deal with the abnormality of the vehicle battery at the earliest possible timing, thereby ensuring safe driving of the vehicle. Realized.

Further, in the on-vehicle battery abnormality detection device of the present invention, the storage means stores at least a contact resistance threshold value for determining the connection state of the busbar as the resistance threshold value. With this structure, the abnormality determination means can detect an abnormality in the fastening portion of the busbar by determining an abnormality in the vehicle-mounted battery using the contact resistance threshold.

Further, the vehicle battery abnormality detection apparatus of the present invention further includes vehicle state determination means for determining the state of the vehicle. The abnormality determining means determines that the on-vehicle battery is abnormal when the busbar resistance value is greater than or equal to the contact resistance threshold value. With this structure, when the amount of current flowing through the vehicle battery is small, such as when the vehicle is stopped, the abnormality determining means can determine whether the vehicle battery is abnormal using the contact resistance threshold.

Further, in the on-vehicle battery abnormality detection device of the present invention, the vehicle state determination means determines the vehicle state using at least the vehicle speed, the accelerator opening or the current value of the vehicle. With this structure, the abnormality detection device can accurately detect an abnormality in the vehicle-mounted battery according to the state of the vehicle.

Further, in the vehicle battery abnormality detection device of the present invention, the current measuring means for measuring the current flowing through the vehicle battery, the voltage measuring means for measuring the voltage applied to the bus bar between the battery modules, and the current measuring means a busbar resistance calculation means for calculating a first busbar resistance value of the busbar using the first current value measured by the voltage measurement means and the first voltage value measured by the voltage measurement means; and a resistance threshold value of the busbar is stored. storage means; abnormality determination means for comparing the first bus bar resistance value and the resistance threshold value to determine abnormality of the vehicle battery; input/output limiting means for limiting the input/output of the busbar resistance calculating means, and notification means for notifying the occupants of the vehicle, when the input/output of the onboard battery is limited by the input/output limiting means Further, using the second current value measured by the current measuring means and the second voltage value measured by the voltage measuring means, the second busbar resistance value is calculated, and the abnormality determining means further: The second bus bar resistance value and the resistance threshold value are compared to determine abnormality of the vehicle battery. to notify the abnormality of the vehicle battery. With this structure, after the abnormal state of the vehicle-mounted battery is resolved by the input/output limiting means, the abnormality of the vehicle-mounted battery is determined again by the abnormality determination means. Anomalies can be detected.

Further, the vehicle-mounted battery abnormality detection apparatus of the present invention further includes vehicle state determination means for determining the state of the vehicle. The abnormality determining means determines that the on-vehicle battery is abnormal when the first busbar resistance value is greater than or equal to the resistance threshold value. With this structure, the abnormality detection device can accurately detect an abnormality in the vehicle-mounted battery according to the state of the vehicle, and can also appropriately protect peripheral components in the vicinity of the busbar.

Further, in the vehicle battery abnormality detection device of the present invention, the vehicle battery is determined to be abnormal when the second bus bar resistance value becomes equal to or greater than the resistance threshold value by the abnormality determination means. With this structure, when the vehicle is running, the busbar resistance value immediately becomes higher than the contact resistance threshold value, but an abnormality in the fastening point can be detected without using the contact resistance threshold value.

Further, in the on-vehicle battery abnormality detection device of the present invention, the storage means stores at least a first conductor resistance threshold value for determining the state of the busbar or the state of peripheral components disposed near the busbar as the resistance threshold value. A second conductor resistance threshold to be determined is stored. With this structure, the abnormality detection device uses the second conductor resistance threshold value to appropriately protect the peripheral parts near the busbar, and uses the first conductor resistance threshold value to bring the vehicle to an emergency stop to ensure the safety of the occupants. can be reliably protected.

Further, in the vehicle battery abnormality detection device of the present invention, the abnormality determination means uses the second conductor resistance threshold as the resistance threshold. Peripheral parts near the busbar usually have a lower heat resistance temperature than the busbar, but the abnormality determination means uses the second conductor resistance threshold value to determine the abnormality, so that the peripheral parts near the busbar are also appropriately protected. can do.

Further, in the vehicle battery abnormality detection device of the present invention, the vehicle state determination means determines the vehicle state using at least the vehicle speed, the vehicle accelerator opening, or the first current value. With this structure, the abnormality detection device can accurately detect an abnormality in the vehicle-mounted battery according to the state of the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a perspective view and FIG. 1B is a plan view illustrating a vehicle equipped with an abnormality detection device for a vehicle-mounted battery according to an embodiment of the present invention; 1 is a block diagram illustrating an abnormality detection device for an in-vehicle battery according to an embodiment of the present invention; FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a top view explaining the vehicle battery which is one Embodiment of this invention. 1 is a timing chart for explaining an in-vehicle battery abnormality detection device according to an embodiment of the present invention; 1 is a flow chart illustrating a control method in an abnormality detection device for an in-vehicle battery according to an embodiment of the present invention;

Hereinafter, an abnormality detection device 10 (hereinafter referred to as "abnormality detection device 10") for a vehicle battery 12 according to an embodiment of the present invention will be described in detail with reference to the drawings. In the description of the present embodiment, in principle, the same reference numbers are used for the same members, and repeated descriptions are omitted.

FIG. 1A is a perspective view illustrating a vehicle 11 equipped with an abnormality detection device 10 (see FIG. 2) of this embodiment. FIG. 1(B) is a plan view illustrating an arrangement state of the vehicle-mounted battery 12 of the present embodiment. FIG. 2 is a block diagram illustrating the abnormality detection device 10 of this embodiment. FIG. 3 is a top view illustrating the vehicle-mounted battery 12 of this embodiment.

As shown in FIG. 1A, a vehicle 11 such as an automobile or a train is equipped with an on-vehicle battery 12 (see FIG. 1B) for supplying electric power to a motor and various electrical components. In the case where the vehicle 11 is an automobile, EV (Electrical Vehicle), HEV (Hybrid Electrical Vehicle), PHEV (Plug-in Hybrid Electrical Vehicle) and the like have been popularized in recent years. These vehicles 11 are equipped with vehicle-mounted batteries 12 having a high power storage function.

FIG. 1A shows a state in which a vehicle 11 having an in-vehicle battery 12 is viewed from below. The vehicle 11 mainly includes a vehicle body 13 and a battery arrangement area 15 near the bottom surface 14 of the vehicle 11. A vehicle battery 12 in which a plurality of battery modules 12A are connected in series, and electric power supplied from the vehicle battery 12 are mainly provided. and a tire (not shown) rotated by the driving force of the drive motor 31 (see FIG. 2).

As shown in FIG. 1B, in the battery arrangement area 15 of the vehicle 11, the battery modules 12A of the vehicle-mounted battery 12 are arranged in a matrix. The battery module 12</b>A has, for example, a rectangular parallelepiped shape, and its longitudinal direction is arranged along the front-rear direction of the vehicle 11 . By efficiently arranging a large number of battery modules 12A in the battery arrangement area 15, the continuous travel distance of the vehicle 11 can be extended.

As shown in FIG. 2, the abnormality detection device 10 includes an electronic control unit 21, a current measurement means 22, a voltage measurement means 23, a storage means 24, a busbar resistance calculation means 25, an abnormality determination means 26, an input/output It has restriction means 27 , vehicle state determination means 28 , and notification means 29 . The abnormality detection device 10 safely controls the vehicle-mounted battery 12, and when detecting an abnormality of the vehicle-mounted battery 12, promptly notifies the occupant of the vehicle 11 of the abnormality, so that the occupant can The vehicle battery 12 can be repaired at an early stage, and the vehicle 11 can run safely.

Each battery module 12A (see FIG. 1(B)) that constitutes the vehicle battery 12 is, for example, a high voltage power source of 350V. Vehicle-mounted battery 12 is connected to drive motor 31 via inverter 30 and supplies power to drive motor 31 . The drive motor 31 outputs power for driving drive wheels (not shown) of the vehicle 11 .

The electronic control unit 21 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., and executes various calculations for vehicle control. The electronic control unit 21 is started by, for example, pressing the ignition switch 32 of the vehicle 11 while the driver steps on the brake (not shown).

The current measuring means 22 is, for example, a current sensor arranged in a BCU (Battery Control Unit) (not shown), and measures the value of the current flowing through the vehicle battery 12 as a whole. The current measuring means 22 periodically repeats the measurement of the current value and inputs the measured data to the storage means 24 .

The voltage measuring means 23 is, for example, a voltage detection circuit connected near the fastening points at both ends of each bus bar 41 (see FIG. 3) disposed between each battery module 12A. The voltage measuring means 23 measures the potential difference between the battery modules 12A when current flows through the vehicle-mounted battery 12 as the voltage value of each bus bar 41 . The voltage measuring means 23 periodically repeats the measurement of the voltage value and inputs the measured data to the storage means 24 .

The storage means 24 is composed of a non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read-only Memory), for example, and stores various data necessary for controlling the vehicle 11 . As one of the various data, the storage means 24 stores a resistance threshold value used when the abnormality determination means 26 determines an abnormality of the vehicle-mounted battery 12 .

Although the details will be described later, the resistance thresholds include a first conductor resistance threshold used when determining the state of the busbar 41 and a second conductor resistance threshold used when determining the state of peripheral components arranged in the vicinity of the busbar 41. A conductor resistance threshold value and a connection resistance threshold value used when determining the connection state of the bus bar 41 are stored.

In addition, the storage means 24 stores the current value and the voltage value input from the current measurement means 22 and the voltage measurement means 23 for each measurement, and also stores the busbar resistance value and the like calculated by the busbar resistance calculation means 25. .

The busbar resistance calculation means 25 calculates the busbar resistance value of each busbar 41 using the current value and voltage value stored in the storage means 24 . Then, the busbar resistance calculation means 25 inputs the calculated busbar resistance value to the storage means 24 .

The abnormality determination means 26 uses the resistance threshold value and the busbar resistance value stored in the storage means 24 to determine whether or not the vehicle-mounted battery 12 is in an abnormal state. Then, the abnormality determination means 26 inputs the determination result to the storage means 24 .

The input/output limiting means 27 limits input/output of the vehicle battery 12 when the abnormality determination means 26 determines that the vehicle battery 12 is in an abnormal state. For example, when the bus bar 41 becomes overheated while power is being output from the vehicle-mounted battery 12 to the drive motor 31, and the above abnormality determination is made, the input/output limiting means 27 reduces the power output from the vehicle-mounted battery 12 to the drive motor 31. limit the amount of power output to 31; Similarly, when the vehicle battery 12 is regenerated and the abnormality determination is made, the input/output limiting means 27 limits the amount of power input from the drive motor 31 to the vehicle battery 12 .

The vehicle state determination means 28 is, for example, a speed sensor 33 that measures the speed of the vehicle 11 and an accelerator opening sensor 34 that measures the opening of an accelerator (not shown) of the vehicle 11 . Also, as the vehicle state determination means 28, the current value measured by the current measurement means 22 stored in the storage means 24 may be used. Then, the vehicle state determination means 28 inputs the determination result to the storage means 24 .

The notification means 29 is, for example, a sound that gives an audible notification to the occupant of the vehicle 11, an image that gives an audible notification to the occupant, a warning lamp, or the like. The voice is notified using a speaker (not shown) provided in the vehicle 11 . The image is reported using a screen of a navigation device (not shown) installed in the vehicle 11 or the like. In addition, the warning lamp is displayed on an instrument panel (not shown) of the vehicle 11 to notify.

FIG. 3 shows a portion of the vehicle battery 12 and shows a state in which the battery modules 12A are connected in series via the busbars 41. As shown in FIG. In the storage case 42 of the battery module 12A, a plurality of battery cells 43 are arranged at equal intervals with small gaps between them. The battery cell 43 is, for example, a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. A positive electrode terminal 44 and a negative electrode terminal 45 are provided on the upper surface of each battery cell 43 , and adjacent battery cells 43 are electrically connected to each other by a connection plate 46 . The connection plate 46 is made of, for example, a copper plate having excellent electrical conductivity, and is fastened to the positive electrode side terminal 44 and the negative electrode side terminal 45 via nuts (not shown) or the like.

As shown, in the battery module 12A on the upper side of the page, the connection plate 46 connected to the positive terminal 44 extends from the left end of the page to the outside of the storage case 42, and is connected to the negative terminal 45 from the right end of the page. A connection plate 46 extends to the outside of the storage case 42 . In the battery module 12A in the middle of the page, the connection plate 46 connected to the negative terminal 45 extends from the left end of the page to the outside of the storage case 42, and the connection plate 46 connected to the positive terminal 44 extends from the right end of the page. lead out to the outside of the storage case 42 . In the battery module 12A at the bottom of the page, the connection plate 46 connected to the positive terminal 44 extends from the left end of the page to the outside of the storage case 42, and the connection plate 46 connected to the negative terminal 45 extends from the right end of the page. lead out to the outside of the storage case 42 .

That is, the connection plates 46 connected to the positive terminal 44 or the negative terminal 45 are alternately led out in the vertical direction of the paper on both the left and right sides of the battery module 12A on the paper. By connecting the bus bar 41 to the connection plate 46 between the adjacent battery modules 12A, a serial connection structure of the vehicle battery 12 is realized. The connecting plate 46 led out to the outside of the storage case 42 and the bus bar 41 are fastened together via fastening members 47 such as bolts and nuts.

Here, the bus bar 41 is made of, for example, a copper material having excellent electrical conductivity, and has a higher thermal conductivity and a lower heat capacity than the battery cells 43 in the battery module 12A. A high temperature state is reached before the battery cell 43 . In particular, in the fastening region of the busbar 41 indicated by the circle 48 and its peripheral region, the busbar 41 is connected to the connecting plate 46, the end plate 49 formed of resin or steel plate, or the lid portion (not shown) of the storage case 42. or are closely spaced.

Although the details will be described later, peripheral parts such as the connection plate 46, the end plate 49, and the cover of the storage case 42 have a lower heat resistance temperature than the busbar 41 and are easily affected by the heat generated by the busbar 41. FIG. These peripheral parts may be deformed and destroyed by the heat transferred from the busbar 41, which may impair the safety of the battery module 12A. Therefore, by controlling the heat generation temperature of the bus bar 41 so as not to exceed the heat resistance temperature of these peripheral components, the vehicle battery 12 can be operated safely. A circle mark 50 shown on the upper surface of the connection plate 46 indicates a voltage measurement point.

Next, FIG. 4 is a timing chart for explaining changes in the busbar resistance value and the like according to the state of the vehicle 11 in the abnormality detection device 10 (see FIG. 2) of this embodiment. FIG. 5 is a flowchart illustrating an example of a control method in the abnormality detection device 10 of this embodiment.

4 shows the current value of the vehicle-mounted battery 12, the temperature of the busbar 41 (see FIG. 3), and the busbar resistance value, which change according to the state of the vehicle 11. FIG.

As described above, in the present embodiment, the busbar resistance value of each busbar 41 is calculated by the busbar resistance calculator 25 (see FIG. 2). The busbar resistance value includes the conductor resistance value and the contact resistance value. is

The conductor resistance value is a resistance value that depends on the electrical resistivity and shape of the metal that constitutes the busbar 41, is highly temperature dependent, and is the resistance value of the busbar 41 itself. Then, when current flows through the busbar 41 and the temperature of the busbar 41 rises, the conductor resistance value also increases.

On the other hand, the contact resistance value is the resistance value generated when metals are fastened together, and in this embodiment, it is the resistance value at the fastening point between the bus bar 41 and the connection plate 46 indicated by the circle 48 in FIG. . If the vehicle battery 12 deteriorates over time or foreign matter enters the fastening portion during manufacturing or the like, current flows through the bus bar 41 and the contact resistance value increases.

As shown in the figure, first, when the vehicle 11 is stopped, current does not flow through the vehicle-mounted battery 12, and the temperature of the busbar 41 and the busbar resistance value are also low. Next, when the ignition of the vehicle 11 is turned on, no current continues to flow through the vehicle-mounted battery 12, and the temperature of the busbar 41 and the busbar resistance value are also low. Next, when the vehicle 11 is preparing to run, a small amount of current flows through the vehicle-mounted battery 12, so that the temperature of the busbar 41 and the resistance value of the busbar are slightly increased.

If, with the vehicle 11 stopped, the busbar resistance suddenly rises above a preset resistance threshold value, the cause of the sudden rise is the contact resistance. It can be regarded as an abnormality of the fastening point of Therefore, although the details will be described later using FIG. 5, when the vehicle state determination means 28 (see FIG. 2) determines that the vehicle 11 is in a stopped state, the abnormality detection device 10 uses the contact resistance threshold value. The abnormality detection of the vehicle-mounted battery 12 is performed by the abnormality detection method (steps S11 to S16).

Next, during normal running of the vehicle 11, more current flows than when the vehicle 11 is preparing to run, so that the temperature of the busbar 41 and the resistance value of the busbar are increased. Next, when the vehicle 11 is rapidly accelerated, more current flows than when the vehicle 11 is normally running, so that the temperature of the busbar 41 and the busbar resistance value are further increased.

If the busbar resistance suddenly rises above a preset resistance threshold value while the vehicle 11 is running, the cause is largely due to either or both of the contact resistance and the conductor resistance. As a result, it can be regarded as an abnormality in the fastening portion or an abnormality in the bus bar 41 or peripheral parts of the bus bar 41 . Therefore, although the details will be described later with reference to FIG. 5, when the vehicle state determination means 28 (see FIG. 2) determines that the vehicle 11 is in the running state, the abnormality detection device 10 detects that the first conductor Abnormality detection of the vehicle-mounted battery 12 is performed by the abnormality detection method (steps S11 to S21) using the resistance threshold value or the second conductor resistance threshold value.

Next, when the vehicle 11 decelerates, the current is lower than when the vehicle 11 is suddenly accelerated or when the vehicle 11 is normally traveling, so that the temperature of the busbar 41 and the busbar resistance value are also lower than when the vehicle 11 is rapidly accelerating. do.

If the busbar resistance suddenly rises above a preset resistance threshold value while the vehicle 11 is running, the cause is largely due to either or both of the contact resistance and the conductor resistance. As a result, it can be regarded as an abnormality in the fastening portion or an abnormality in the bus bar 41 or peripheral parts of the bus bar 41 . Therefore, although the details will be described later with reference to FIG. 5, when the vehicle state determination means 28 (see FIG. 2) determines that the vehicle 11 is in the running state, the abnormality detection device 10 detects that the first conductor Abnormality detection of the vehicle-mounted battery 12 is performed by the abnormality detection method (steps S11 to S21) using the resistance threshold value or the second conductor resistance threshold value.

Finally, when the vehicle 11 stops after running, current does not flow to the on-vehicle battery 12, and the temperature of the bus bar 41 and the bus bar resistance gradually decrease to a low state.

If, with the vehicle 11 stopped, the busbar resistance suddenly rises above a preset resistance threshold value, the cause of the sudden rise is the contact resistance. It can be regarded as an abnormality of the fastening point of Therefore, although the details will be described later using FIG. 5, when the vehicle state determination means 28 (see FIG. 2) determines that the vehicle 11 is in a stopped state, the abnormality detection device 10 uses the contact resistance threshold value. The abnormality detection of the vehicle-mounted battery 12 is performed by the abnormality detection method (steps S11 to S16).

Although the timing chart shown in FIG. 4 describes the case where the vehicle state determining means 28 (see FIG. 2) determines the state of the vehicle 11 from the current value flowing through the vehicle-mounted battery 12, it is limited to this case. isn't it. For example, the vehicle state determination means 28 may determine the state of the vehicle 11 using the speed sensor 33 (see FIG. 2), or determine the state of the vehicle 11 using the accelerator opening sensor 34 (see FIG. 2). Even if you do. Further, in the present embodiment, different abnormality detection methods are used depending on whether the vehicle 11 is in a stopped state or in a running state. Further, the state of the vehicle 11 is classified in detail to detect an abnormality in the on-vehicle battery 12. even if it is.

As shown in FIG. 5, first, in step S11, when an occupant such as a driver gets into the vehicle 11 and presses the ignition switch 32, the vehicle 11 is turned on. At this time, the abnormality detection device 10 (see FIG. 2) of the vehicle 11 is also turned on.

Next, in step S12, the electronic control unit 21 (see FIG. 2) controls the current measuring means 22, the voltage measuring means 23 and the storage means 24 (see FIG. 2), and the current measuring means 22 controls the vehicle battery 12. The value of the flowing current is measured and input to the storage means 24 . On the other hand, the voltage measuring means 23 measures the voltage value applied to each bus bar 41 (see FIG. 3) between each battery module 12A (see FIG. 3) and inputs it to the storage means 24. FIG. Then, the storage means 24 stores the current value and the voltage value input from the current measurement means 22 and the voltage measurement means 23 . The above current value and voltage value also correspond to the first current value and first voltage value described in the claims.

Next, in step S13, the electronic control unit 21 controls the busbar resistance calculation means 25 and the storage means 24, and the busbar resistance calculation means 25 uses the current and voltage values stored in the storage means 24 to A busbar resistance value of the busbar 41 is calculated and input to the storage means 24 . Then, the storage means 24 stores the busbar resistance value input from the busbar resistance calculation means 25 . The above busbar resistance value also corresponds to the first busbar resistance value described in the claims.

Next, in step S14, the electronic control unit 21 controls the vehicle state determination means 28 and the storage means 24, and the vehicle state determination means 28 stores, for example, the storage means 24 as described above with reference to FIG. The state of the vehicle 11 is determined using the obtained current value.

Then, in step S14, if the vehicle state determination means 28 determines that the vehicle 11 is stopped, in step S15, the electronic control unit 21 controls the abnormality determination means 26 and the storage means 24, The abnormality determination means 26 determines whether or not the vehicle battery 12 is abnormal using the busbar resistance value stored in the storage means 24 and the contact resistance threshold value, which is one of the resistance threshold values.

Here, in the present embodiment, as the resistance threshold, a first conductor resistance threshold set from the heat resistant temperature of the bus bar 41 itself, a second conductor resistance threshold set from the heat resistant temperature of peripheral parts of the bus bar 41, and the contact resistance threshold are stored in the storage means 24 . The first conductor resistance threshold is a numerical value set according to the material and shape of the bus bar 41, and is set to 300 μΩ in this embodiment. The second conductor resistance threshold is set in the area indicated by the circle 48 in FIG. and a numerical value set according to its shape, and is set to 100 μΩ in this embodiment. The contact resistance threshold is the resistance value at the fastening point between the busbar 41 and the connection plate 46 indicated by the circle 48 in FIG. 3, and is set to 50 μΩ in this embodiment. The resistance threshold can be arbitrarily changed in design according to the materials of the bus bar 41 and its peripheral parts.

If YES in step S15, the busbar resistance value is equal to or greater than the contact resistance threshold value of 50 μΩ, the abnormality determining means 26 detects an abnormality in the vehicle battery 12 due to foreign matter entering the fastening portion. determine that it has occurred.

Next, in step S16, the electronic control unit 21 controls the notification means 29, and the notification means 29 displays a warning lamp on the instrument panel (not shown) of the vehicle 11 to warn the occupant of the vehicle 11 that the on-vehicle battery 12 is notified that an abnormality has occurred. After that, the occupant who received the notification brings the vehicle 11 to the dealer and receives appropriate treatment, thereby extinguishing the warning lamp.

If the busbar resistance value is smaller than the contact resistance threshold value of 50 μΩ in step S15, the abnormality determining means 26 determines that there is no foreign matter mixed in the fastening portion, and that the vehicle battery 12 is abnormal. Determine that it has not occurred. After that, the process returns to step S12, and the above-described abnormality detection method is repeated at predetermined intervals.

Next, when the vehicle state determination means 28 determines that the vehicle 11 is in the vehicle state in step S14, the electronic control unit 21 controls the abnormality determination means 26 and the storage means 24 in step S17. The abnormality determination means 26 determines whether or not the vehicle battery 12 is abnormal using the busbar resistance value stored in the storage means 24 and the second conductor resistance threshold, which is one of the resistance thresholds. .

If YES in step S17, the busbar resistance value is equal to or greater than the second conductor resistance threshold value of 100 μΩ, the abnormality determination means 26 determines whether an abnormality has occurred in the busbar 41 or its peripheral parts, It is determined that an abnormality has occurred in the in-vehicle battery 12 due to, for example, contamination of a foreign object in the location.

In step S17, if the busbar resistance value is smaller than the second conductor resistance threshold value of 100 μΩ, the abnormality determination means 26 determines whether an abnormality has occurred in the busbar 41 or its peripheral parts, It is determined that there is no foreign matter mixed into the vehicle battery 12 and that there is no abnormality in the vehicle battery 12 . After that, the process returns to step S12, and the above-described abnormality detection method is repeated at predetermined intervals.

Next, in step S18, the electronic control unit 21 controls the input/output limiting means 27, and the input/output limiting means 27 limits the input/output of the battery 12 for vehicle use. For example, when power is output from the vehicle battery 12 to the drive motor 31, the amount of output is reduced, the amount of current flowing through the vehicle battery 12 is reduced, and the heat generation temperature of the bus bar 41 is reduced to a desired temperature. down to

Next, in step S19, the electronic control unit 21 controls the current measurement means 22, the voltage measurement means 23 and the storage means 24, and the current measurement means 22 measures the current value flowing through the vehicle battery 12 after the input/output limitation. Measured and input to storage means 24 . On the other hand, the voltage measuring means 23 also measures the voltage value applied to each bus bar 41 between each battery module 12A after the input/output restriction, and inputs it to the storage means 24 . Then, the storage means 24 stores the current value and the voltage value input from the current measurement means 22 and the voltage measurement means 23 . The current value and voltage value measured after the input/output limitation corresponds to a second current value and a second voltage value described in claims.

Next, in step S20, the electronic control unit 21 controls the busbar resistance calculation means 25 and the storage means 24, and the busbar resistance calculation means 25 calculates the current value and voltage value after the input/output limitation stored in the storage means 24. is used to calculate the busbar resistance value of each busbar 41 after the input/output limitation, and the value is input to the storage means 24 . Then, the storage means 24 stores the busbar resistance value input from the busbar resistance calculation means 25 . The busbar resistance value calculated after the input/output limitation corresponds to the second busbar resistance value described in the claims.

Next, in step S21, the electronic control unit 21 controls the abnormality determination means 26 and the storage means 24, and the abnormality determination means 26 uses the busbar resistance value and the second conductor resistance threshold stored in the storage means 24 to , determines whether or not the on-vehicle battery 12 is abnormal.

Then, in step S21, if the busbar resistance value is again equal to or greater than the second conductor resistance threshold value of 100 μΩ, the abnormality determination means 26 determines whether an abnormality has occurred in the busbar 41 or its peripheral components. It is determined that an abnormality has occurred in the in-vehicle battery 12 due to, for example, foreign matter entering the fastening portion.

Next, in step S16, the electronic control unit 21 controls the notification means 29, and the notification means 29 displays a warning lamp on the instrument panel (not shown) of the vehicle 11 to warn the occupant of the vehicle 11 that the on-vehicle battery 12 is notified that an abnormality has occurred. After that, the occupant who received the notification brings the vehicle 11 to the dealer and receives appropriate treatment, thereby extinguishing the warning lamp.

If the busbar resistance value is smaller than the second conductor resistance threshold value of 100 μΩ in step S21, the abnormality determination means 26 determines that an abnormality has occurred in the busbar 41 or its peripheral parts, or that the fastening point has occurred. It is determined that there is no foreign matter mixed into the vehicle battery 12 and that there is no abnormality in the vehicle battery 12 . After that, the process returns to step S12, and the above-described abnormality detection method is repeated at predetermined intervals.

As described above, when the vehicle 11 is stopped, no current flows through the vehicle battery 12, or the amount of current flowing through the vehicle battery 12 is small. Therefore, the busbar resistance value is greatly affected by the contact resistance value. Therefore, in the abnormality detection device 10 of the present embodiment, when the vehicle 11 is stopped, the contact resistance threshold value is used for determination, so that the abnormality of the vehicle-mounted battery 12 is regarded as an abnormality caused by foreign matter entering the fastening portion. I can do this. Then, the abnormality detection device 10 immediately notifies the occupant of the vehicle 11 of the abnormality of the on-vehicle battery 12 via the notification means 29, so that the occupant can deal with the abnormality of the fastening point at the earliest possible timing. Therefore, safe driving of the vehicle 11 is realized.

On the other hand, when the vehicle 11 is running, the amount of current flowing through the vehicle-mounted battery 12 increases, and the bus bar 41 quickly reaches a high temperature. Since the conductor resistance value is highly dependent on temperature, the busbar resistance value also rises immediately.

Therefore, in the abnormality detection device 10 of the present embodiment, when the vehicle 11 is running, the abnormality of the on-vehicle battery 12 is determined using the second conductor resistance threshold derived from the heat resistance temperature of the peripheral parts in the vicinity of the bus bar 41. ing. In other words, the peripheral parts in the vicinity of the busbar 41 usually have a lower heat-resistant temperature than the busbar 41, and may be deformed or destroyed by being exposed to the heat-resistant temperature of the busbar 41 for a long time. Therefore, in the abnormality detection device 10, by performing abnormality detection using the second conductor resistance threshold, the temperature of the busbar 41 is prevented from becoming equal to or higher than the temperature determined by the second conductor resistance threshold. Nearby peripheral parts are prevented from being deformed and destroyed.

Furthermore, by preventing the temperature of the busbars 41 from becoming equal to or higher than the temperature determined by the second conductor resistance threshold, the heat generated by the busbars 41 is transmitted to the battery cells 43 of the battery modules 12A. The cell 43 is also prevented from falling into a runaway mode.

Further, as described above, when the vehicle 11 is running, the busbar resistance value immediately rises sharply, so that the abnormality determination means 26 cannot determine using the contact resistance threshold, and the abnormality of the fastening point is discovered. becomes difficult.

Therefore, in the abnormality detection device 10, when the vehicle 11 is running, the abnormality determining means 26 once determines that the vehicle battery 12 is abnormal, and then the input/output of the vehicle battery 12 is restricted by the input/output limiting means 27. . After the abnormal state of the vehicle-mounted battery 12 is resolved by the input/output limiting means 27, the abnormality of the vehicle-mounted battery 12 is determined again by the abnormality determination means 26, so that the contact resistance threshold is not used. Abnormalities in fastening points can be detected. In other words, even if the input/output of the vehicle-mounted battery 12 is restricted by the input/output limiting means 27, when the abnormality determination means 26 determines that the vehicle-mounted battery 12 is abnormal, the contact resistance value is high. This is because it can be assumed that there is an abnormality in the fastening portion.

On the other hand, if the abnormality determination means 26 determines that there is no abnormality in the vehicle battery 12 after the input/output limiting means 27 eliminates the abnormality, the fastening portion is also normal. Furthermore, the temperature of the busbar 41 is also suppressed below the heat-resistant temperature of the peripheral parts in the vicinity of the busbar 41, so that the peripheral parts in the vicinity of the busbar 41 are not deformed or destroyed.

In the present embodiment, the case where the abnormality determination means 26 of the abnormality detection device 10 makes a determination using the second conductor resistance threshold when the vehicle 11 is running has been described, but the present invention is not limited to this case. do not have. For example, in step S17 of FIG. 5, a first conductor resistance threshold, which is one of the resistance thresholds, may be further used to determine whether or not the vehicle-mounted battery 12 is abnormal. In this case, when the busbar resistance value is greater than or equal to the second conductor resistance threshold value and less than or equal to the first conductor resistance threshold value, the input/output limiting means 27 limits the input/output of the vehicle-mounted battery 12, but the busbar resistance value is , the safety of the occupants of the vehicle 11 can be given priority by stopping the vehicle 11 in an emergency. In addition, various modifications are possible without departing from the gist of the present invention.

REFERENCE SIGNS LIST 10 abnormality detection device 11 vehicle 12 vehicle battery 12A battery module 21 electronic control unit 22 current measurement means 23 voltage measurement means 24 storage means 25 busbar resistance calculation means 26 abnormality determination means 27 input/output restriction means 28 vehicle state determination means 29 notification means 31 drive motor 33 speed sensor 34 accelerator opening sensor 41 bus bar 42 storage case 43 battery cell 46 connection plate 47 fastening member

Claims (7)

An abnormality detection device for an in-vehicle battery in which a plurality of battery modules are connected in series via a bus bar and for detecting an abnormality in an in-vehicle battery mounted in a vehicle,
a current measuring means for measuring the current flowing through the vehicle battery;
voltage measuring means for measuring the voltage applied to the busbar between the battery modules;
busbar resistance calculation means for calculating a first busbar resistance value of the busbar using the first current value measured by the current measurement means and the first voltage value measured by the voltage measurement means;
storage means for storing the resistance threshold value of the busbar;
Abnormality determination means for comparing the first busbar resistance value and the resistance threshold value to determine an abnormality of the on-vehicle battery;
input/output limiting means for limiting input/output of the vehicle-mounted battery when the abnormality determination means determines that the vehicle-mounted battery is abnormal;
and a notification means for notifying an occupant of the vehicle,
When the input/output of the automotive battery is restricted by the input/output restricting means,
The busbar resistance calculation means further calculates a second busbar resistance value using the second current value measured by the current measurement means and the second voltage value measured by the voltage measurement means. ,
The abnormality determination means further compares the second busbar resistance value with the resistance threshold to determine an abnormality of the on-vehicle battery,
The informing means notifies the occupant of the abnormality in the vehicle battery when the abnormality determination means again determines that the vehicle battery is abnormal. Anomaly detector. The storage means stores, as the resistance threshold value, at least a first conductor resistance threshold value for determining the state of the busbar or a second conductor resistance threshold value for determining the state of peripheral components disposed near the busbar. 2. An abnormality detection device for a vehicle-mounted battery according to claim 1 , wherein: and vehicle state determination means for determining the state of the vehicle,
When the vehicle state determination means determines that at least the vehicle is in a running state,
3. The vehicle-mounted vehicle according to claim 2 , wherein the abnormality determination means determines that the vehicle-mounted battery is abnormal when the first busbar resistance value becomes equal to or greater than the first conductor resistance threshold value. battery abnormality detection device. 4. The vehicle-mounted vehicle according to claim 3 , wherein the abnormality determining means determines that the vehicle-mounted battery is abnormal when the second busbar resistance value becomes equal to or greater than the second conductor resistance threshold value. battery abnormality detection device. 5. The vehicle state determining means determines the state of the vehicle using at least the speed of the vehicle, the degree of acceleration of the vehicle, or the first current value. An anomaly detection device for an in-vehicle battery described above. and vehicle state determination means for determining the state of the vehicle,
The storage means stores, as the resistance threshold value, at least a contact resistance threshold value for determining the connection state of the bus bar,
When the vehicle state determination means determines that at least the vehicle is in a stopped state,
2. The vehicle-mounted battery according to claim 1 , wherein the abnormality determination means determines that the vehicle-mounted battery is abnormal when the first busbar resistance value becomes equal to or greater than the contact resistance threshold value. Anomaly detector. 7. The on-vehicle device according to claim 6 , wherein the vehicle state determination means determines the state of the vehicle using at least the speed of the vehicle, the degree of acceleration of the vehicle, or the first current value. Battery anomaly detector.

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