JP2017121147A - Protective device of low-voltage battery for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protective device of low-voltage battery for vehicle, capable of preventing battery exhaustion of a low-voltage battery after charging completion without incurring appearance degradation and a cost increase of a vehicle.SOLUTION: The protective device of low-voltage battery for vehicle shuts down power supply from a second battery 10 to a low-voltage operation apparatus 9 when a power supply state in which the second battery 10 installed on a vehicle supplies electric power to the low-voltage operation apparatus 9 continues for over a predetermined time after charging into a first battery 6 mainly used for vehicle drive is completed by an external power supply device 7.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a protection device for a low voltage battery for a vehicle that can be fed from an external power feeding device.

  2. Description of the Related Art In recent years, so-called electric vehicles that run by driving a power source such as a motor using electric energy charged in a high-voltage battery mounted on a vehicle have been spreading. In this type of electric vehicle, the high voltage battery is charged by connecting an external power supply device to the vehicle body via a power supply cable, for example.

  Patent Document 1 shows an example of an electric vehicle that can be charged by an external power supply device. In particular, this document describes that normal charging and rapid charging can be selected as high-voltage battery charging by an external power feeding device, and a charging circuit corresponding to each is provided.

2011-223796 gazette

  When charging a high-voltage battery using an external power supply device, when the user wants to check the progress status (for example, the amount of charge) during charging, when there is no display device on the external power supply device side, a key-on operation is performed on the vehicle. In some cases, the engine is in a start-up preparation state and checked using a display device such as an instrument panel. At that time, the user forgets the key-off operation after the confirmation work, and then the start preparation state is continued, so that a low-voltage battery (not a high-voltage battery mainly used for driving and regenerating with a traveling motor) , A battery used to drive a device operating at a low voltage) may be consumed. In particular, in normal charging, the vehicle is often left for a long time as compared with rapid charging. Therefore, if the start preparation state is continued for a long time, the low voltage battery is increased. In order to solve such a problem, it may be possible to provide an indicator for the driver to check the amount of charge at the power supply port of the vehicle, but this deteriorates the appearance of the vehicle and increases the manufacturing cost.

  At least one embodiment of the present invention has been made in view of the above-described problems, and it is possible to prevent a low-voltage battery for a vehicle that can prevent a low-voltage battery from running out after charging without causing deterioration in the appearance of the vehicle and an increase in cost. An object of the present invention is to provide a battery protection device.

  In order to solve the above-described problem, a vehicle low-voltage battery protection device according to at least one embodiment of the present invention includes an external power feeding unit that feeds power to a first battery mounted on a vehicle from the external power feeding device, and the external power feeding. Battery state determination means for determining whether or not a second battery mounted on the vehicle is in a power supply state supplying power to a low-voltage operating device after charging by the means is completed; and the battery state When the second battery is in the power supply state by the determining means, the power supply state time calculating means for calculating the duration of the power supply state and the duration calculated by the power supply state time calculating means Power supply cutoff means for cutting off the power supply from the second battery to the low-voltage operating device when the predetermined time has elapsed.

  According to the above configuration, when the second battery supplies power to the low-voltage operating device for a predetermined time or longer after the charging of the first battery by the external power supply device, the low-voltage operation is performed from the second battery. The power supply to the equipment is cut off. Thereby, after completion of charging of the first battery, it is possible to effectively prevent the second battery from rising due to the second battery continuing to supply power to the low-voltage operating device.

1 is a schematic diagram illustrating a configuration example of a vehicle 1 in which a vehicle low-voltage battery protection device 110 according to at least one embodiment of the present invention is mounted in an ECU 111. FIG. It is a block diagram which shows the internal structure of the protection apparatus 110 of the low voltage battery for vehicles in ECU111 of FIG. It is a flowchart which shows the control implemented with the protection apparatus 110 of the low voltage battery for vehicles of FIG. 2 for every process.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Absent.

  FIG. 1 is a schematic diagram illustrating a configuration example of a vehicle 1 in which a low-voltage battery protection device 110 for a vehicle according to at least one embodiment of the present invention is mounted in an ECU 111. FIG. 2 is a block diagram showing an internal configuration of the low voltage battery protection device 110 in the ECU 111 shown in FIG. FIG. 3 is a flowchart showing, for each process, control performed by the vehicle low-voltage battery protection device 110 of FIG.

A vehicle 1 shown in FIG. 1 is an electric vehicle including an electric motor 3 as a driving source for traveling.
The electric motor 3 is a motor that can be driven by power or regeneratively, and is, for example, a permanent magnet type synchronous motor. The electric motor 3 is connected to the first battery 6 via the inverter 5, and the DC power stored in the first battery 6 is converted into AC power having a predetermined frequency and supplied by the inverter 5 during power running. Thus, torque can be generated. The power output from the electric motor 3 is transmitted to the left and right drive wheels 16 via the propeller shaft 13, the differential device 12, and the drive shaft 14, and the traveling of the vehicle 1 is realized.

  On the other hand, at the time of regeneration (for example, at the time of vehicle deceleration), the electric motor 3 functions as a generator (generator) by the input torque and generates electric energy. During regeneration, the electric motor 3 generates AC power, and the AC power is DC converted by the inverter 5 and then charged to the first battery 6. As described above, the electric power charged in the first battery 6 is consumed when the electric motor 3 is driven by power, so that a sufficient cruising distance can be obtained. Further, at the time of regeneration, the electric motor 3 generates regenerative torque. The regenerative torque acts as a braking torque (regenerative brake) on the traveling vehicle 1.

  The first battery 6 is a chargeable / dischargeable secondary battery, and is composed of, for example, a secondary battery such as a lithium ion, nickel metal hydride, or lead battery, and is charged with DC power that can be used mainly as driving power for the motor 3. Has been. In this embodiment, the 1st battery 6 is comprised so that electric power feeding is possible via the external electric power feeding means 20 mentioned later.

  The electric energy charged in the first battery 6 may include electric energy generated by regenerative power generation while the vehicle 1 is traveling, in addition to the electric energy supplied by the external power supply means 20.

  The first battery 6 has a charge amount detection function, such as detecting the battery voltage inside and detecting the charge amount. The charge amount of the first battery 6 detected by the detection function is sent as electrical information to the ECU 111 described later. In addition to being used for control in each part of the vehicle 1 based on the received information on the charge amount, the ECU 111 displays the charge amount on a display device (display or the like) provided in the vehicle interior such as an instrument panel, for example. The driver is configured so that the charge amount of the first battery 6 can be confirmed.

  The low-voltage operating device 9 is activated by the electric power supplied from the second battery 10 when the driver inserts a key into the vehicle 1 and sets the vehicle 1 to the ACC or ON position to put the vehicle 1 in a start preparation state. The device group includes, for example, an ECU 111, an instrument panel display device (display, etc.), an in-vehicle air conditioner, and the like.

  The second battery 10 is a battery provided separately from the first battery 6 for the operation of the low-voltage operating device 9. The second battery 10 is a rechargeable secondary battery similar to the first battery 6, but is a battery that operates at a lower voltage than the first battery 6. For example, the operating voltage is 12V, 24V or It is set to about 48V.

The ECU (Electric Control Unit) 111 is a control unit of the vehicle 1 and is constituted by, for example, an electronic arithmetic unit. In the present embodiment, the ECU 111 also functions as a protection device 110 for a low voltage battery for a vehicle by performing various controls necessary for the vehicle 1 based on a predetermined control program installed in advance.
The ECU 111 typically has an input unit for inputting various information from each component included in the vehicle 1, and a storage unit capable of storing various types of input information and various programs and calculation results necessary for performing control. An arithmetic unit that performs arithmetic processing based on these various types of information and an output unit that outputs a control signal to the control device are included.
The ECU 111 is electrically connected to the first battery 6, the inverter 5, the second battery 10, the external power supply means 20, the notification means 21, and the like. The ECU 111 can acquire information about the amount of charge of these batteries from the first battery 6 and the second battery 10 and information about the battery state such as battery temperature. Further, the ECU 111 can also acquire information on whether or not the external power supply device 7 (power supply cable 15) is connected from the external power supply means 20 described later. Further, the ECU 111 may be configured to be able to acquire information about the external power supply device 7 and charging completion via the power supply cable 15 connected to the external power supply means 20.

The external power supply means 20 is configured to be able to supply power to the first battery 6 mounted on the vehicle 1 from an external power supply device 7 provided outside the vehicle 1. The external power supply means 20 is connected to the external power supply device 7 by a power supply cable 15 provided in the external power supply device 7. The external power supply device 7 includes a normal charge type and a quick charge type, and can be selected during power supply. In the quick charge type, the charging current can be set larger than in the normal charge type, and a large capacity can be charged in a shorter time.
The progress of charging by the external power supply means 20 can be confirmed with a display device such as an instrument panel provided in the vehicle as described above.

The notification means 21 is configured to be able to notify a notification purpose by outputting a control signal to a notification device generally mounted on the vehicle 1, for example, a device such as a buzzer or a display. For example, a warning sound that can be audibly recognized by the buzzer device or a display that can be visually recognized by the buzzer device so as to perform a key-off operation of the vehicle 1 to the driver in the passenger compartment by the notification means 21 can do.
Needless to say, the notification device operated by the notification means 21 can employ a wide range of devices that can be recognized by the five senses of the driver in addition to the above example.

  Here, with reference to FIG. 2, the structure of the low voltage battery protection device 110 included in the ECU 111 will be described from a functional viewpoint. The vehicle low-voltage battery protection device 110 is in a power supply state in which the second battery 10 mounted on the vehicle 1 supplies power to the low-voltage operating device 9 after the charging by the external power feeding means 20 is completed. When the second battery 10 is in the power supply state by the battery state determination unit 100 that determines whether or not there is, the power supply state time calculation unit 101 that calculates the duration of the power supply state when the second battery 10 is in the power supply state. And a power supply shut-off means 102 for shutting off the power supply from the second battery 10 to the low-voltage operating device 9 when the duration calculated by the power supply state time calculating means 101 exceeds a predetermined time. Prepare.

  With reference to FIG. 3, the specific content of the vehicle low voltage battery protection control implemented by the vehicle low voltage battery protection device 110 will be described. FIG. 3 is a flowchart showing, for each process, control performed by the vehicle low-voltage battery protection device 110 of FIG.

In the vehicle low-voltage battery protection device 110, first, an external power supply device 7 provided outside the vehicle 1 and an external power supply means 20 mounted on the vehicle 1 are connected via a power supply cable 15. 6 is determined (step S1). When it is determined that charging is started (step S1: YES), the process proceeds to step S2, and when it is not determined that charging is started (step S1: NO), the process returns to step S1.
The start of this control may be started when the ECU 111 receives a charge start signal from the external power supply device 7.

Since the method for determining that charging of the first battery 6 from the external power supply device 7 has started differs depending on the type of the external power supply device 7 and the like, a determination method is determined for each external power supply device 7 corresponding to the vehicle 1 ( For example, in the case of the quick charge type of the CHAdeMO specification, when the ECU 111 detects a connection signal of the power supply cable 15 connected to the vehicle 1 and receives a charge start signal from the external power supply device 7, it is determined that charging is started. , Etc.).

  Subsequently, the protection device 110 for the low-voltage battery for the vehicle monitors the charging status by the external power supply device 7, and then determines whether or not the charging by the external power supply means 20 has been completed (step S2). If it is determined that the charging is finished (step S2: YES), the process proceeds to step S3. If it is not determined that the charging is finished (step S2: NO), the process returns to step S2 to the first battery 6 by the external power supply means 20. Power supply continues.

  The method for determining the end of charging is also different depending on the type of the external power supply device 7 and the like, as in the above-described determination of the start of charging. Therefore, a determination method is determined for each external power supply device 7 corresponding to the vehicle 1 (for example, In the case of the quick charge type of the CHAdeMO specification, the ECU 111 receives a charge end signal from the external power supply device 7, or the charge amount of the first battery 6 by the power supply from the external power supply means 20 is set by the ECU 111 If it is detected that the upper limit charge amount of the first battery has been reached, it is determined that charging has ended, and so on).

  Subsequently, the battery state determination unit 100 of the vehicle low-voltage battery protection device 110 determines whether or not the second battery 10 is in a power supply state in which power is being supplied to the low-voltage operating device 9 ( Step S3). Here, the power supply state refers to a case where the key is inserted into the vehicle 1 and set to the ACC position or the ON position, and the vehicle 1 is in a start preparation state. In this state, power is continuously supplied to 9.

  When the battery state determination unit 100 determines that the vehicle 1 is in the power supply state (step S3: YES), the power supply state calculation unit 101 continues the power supply state after the end of charging. t is counted. On the other hand, when it is not determined that the vehicle 1 is in the power supply state (step S3: NO), the power supply state time calculation unit 101 does not perform the count, and the vehicle low voltage battery protection device 110 performs the vehicle low operation. The voltage battery protection control ends.

The low voltage battery protection device 110 for the vehicle determines whether or not the duration t counted by the power supply state time calculation means 101 exceeds a preset first determination time T1 (step S4). If duration t ≦ first determination time T1 (step S4: NO), the process returns to step S3, and if the power supply state is continued, the power supply state time calculation means 101 continues to count the duration time. If duration t> first determination time T1 (step S4: YES), the process proceeds to step S5 in which the notification means 21 is activated.
The first determination time T1 is, for example, a threshold for determining whether or not the power supply state is continued more than necessary, and the second determination time T1 is determined by the power consumption by the low-voltage operating device 9 in the power supply state. Although it is good to set in the range which does not produce big influence on the charge amount of the battery 10, it can set arbitrarily according to a specification.

  Subsequently, the vehicle low-voltage battery protection device 110 activates the notification means 21 so that the driver performs a key-off operation on the vehicle 1 (step S5).

Next, the process proceeds to step S6 for determining whether or not the key-off operation is completed. If the key-off operation is detected (step S6: YES), the protection control is terminated. If the key-off operation is not detected (step S6: NO), the duration t is continuously counted and the notification means 21 continues to operate, and the next step S7 is performed. move on.

In the driver absence determination step S7, it is determined whether or not the duration t has exceeded the second determination time T2. When the duration time t is equal to or less than the second determination time T2 (step S7: NO), the key-off operation is prompted while returning to step 5 and informing. When the duration t exceeds the second determination time T2 (step S7: YES), the process proceeds to step S8 where the low-voltage operating device 9 is shut down.
The second determination time T2 is a time when it is determined that the charge amount of the second battery 10 is greatly affected, or a time when it is determined that a sufficient time for the driver to check the charged state has elapsed, Is set to a time longer than the first determination time T1, but can be arbitrarily set according to the specification.
Further, as a method for recognizing whether or not there is a driver in the vehicle interior, in addition to the above-described recognition determination by software, for example, it is recognized by hardware information using an imaging device such as a camera provided in the vehicle interior. Alternatively, it may be recognized as hardware based on load information obtained from a weight sensor provided under the seat of the passenger.

In step S8, power supply from the second battery 10 to the low-voltage operating device 9 is cut off by the power supply cut-off means 102, and the protection control of the second battery 10 by the vehicle low-voltage battery protection device 110 ends. . In step S8, for example, the power supply may be interrupted by electrically disconnecting the circuit connecting the second battery 10 and the low-voltage operating device 9 or by appropriately connecting the low-voltage operating device 9 on the load side. You may make it shut down by a simple procedure.

As described above, according to the present embodiment, after the charging of the first battery 6 by the external power supply device 7 is completed, the time during which the second battery 10 supplies power to the low-voltage operating device 9 becomes a predetermined time or more. In this case, power supply from the second battery 10 to the low-voltage operating device 9 is interrupted. Accordingly, it is possible to effectively prevent the second battery 10 from being discharged due to the second battery 10 continuing to supply power to the low-voltage operating device 9 after the charging of the first battery 6 is completed.
In addition, the present disclosure is a response by adding new software to the ECU 111 instead of newly providing an indicator or the like in the vehicle 1. Therefore, the second battery 10 can be prevented from running out without deteriorating the appearance of the vehicle 1 or increasing the manufacturing cost. In addition, a new dedicated ECU is added to give the vehicle 1 the same function, or the software is installed in an ECU that is used for another purpose (for example, an ECU for grasping the driver's arousal status). Thus, a similar function may be provided.

  In the present embodiment, the electric vehicle is exemplified as the vehicle 1. However, the electric vehicle 3 is a hybrid electric vehicle that uses the engine as a driving power source together with the electric motor 3, and is a so-called plug-in that can be charged by an external power feeding device. You may apply to a hybrid electric vehicle.

DESCRIPTION OF SYMBOLS 1 Vehicle 3 Electric motor 5 Inverter 6 1st battery 7 External power supply device 9 Low voltage operation apparatus 10 Second battery 12 Differential device 13 Propeller shaft 14 Drive shaft 15 Power supply cable 16 Drive wheel 20 External power supply means 21 Notification means 100 Battery State determination means 101 Power supply state time calculation means 102 Power supply cut-off means 110 Vehicle low-voltage battery protection device 111 ECU

Claims (1)

An external power supply means for supplying power to the first battery mounted on the vehicle from the external power supply device;
Battery state determination means for determining whether or not the second battery mounted on the vehicle is in a power supply state supplying power to a low-voltage operating device after charging by the external power supply means is completed;
When the second battery is in the power supply state by the battery state determination unit, a power supply state time calculation unit that calculates a duration of the power supply state;
Power supply cutoff means for cutting off power supply from the second battery to the low-voltage operating device when the duration calculated by the power supply state time calculation means exceeds a predetermined time. A low-voltage battery protection device for vehicles.

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