JP6503893B2 - Vehicle charge control device - Google Patents

Description

  The present invention relates to a charge control device for a vehicle.

  Conventionally, in a plug-in hybrid vehicle provided with a quick charging connector, an electric vehicle or the like, a battery assembly provided with a battery unit for storing power is generally used. The battery unit is composed of unit cells called a plurality of cells, and the assembled battery is provided with a cell voltage sensor that detects a voltage for each cell. The charge and discharge control of the battery unit is performed by an ECU, which is control means, based on detection signals from the cell voltage sensors.

  As such a failure diagnosis of a battery pack, there is known a technique of performing a failure diagnosis based on individual cell voltages and the total voltage of the cells (see, for example, "Patent Document 1"). Further, there is known a technique for estimating a voltage based on a cell voltage distribution before failure and a cell voltage distribution after failure (see, for example, “Patent Document 2”).

Japanese Patent Application Publication No. 2003-134675 Patent No. 3698089

In the above-described configuration, when the cell voltage sensor breaks down, the voltage of the cell becomes unknown, and therefore, it is prohibited to perform charging to prevent occurrence of a problem such as ignition of the battery pack due to overcharging. Then, the user is notified of the failure of the cell voltage sensor, and the user who recognizes the failure travels to the dealer to repair the battery pack with only the discharging. However, the dealer may not be able to reach when the remaining charge amount decreases.
The present invention solves the above-mentioned problems and aims to provide a charge control device for a vehicle capable of causing the vehicle to travel without causing overdischarge or overcharge even when the cell voltage sensor is broken. I assume.

  According to the first aspect of the present invention, a plurality of battery cells constituting an on-vehicle battery unit, a vehicle-side charge port connectable to a charge connector connected to an external power supply, the charge port, and each of the battery cells A charging circuit for connecting between them, a charging contactor for switching between the blocking state and the connecting state of the charging circuit, a contactor voltage sensor used for detecting a failure of the charging contactor, and corresponding to each of the battery cells A plurality of cell voltage sensors provided for measuring the voltage of the battery cells, failure detection means for detecting a failure of each of the cell voltage sensors, and control means for performing charge / discharge control of the battery unit The control unit is configured to set the charging circuit such that the charging circuit is in a connected state when a failure of any of the cell voltage sensors is detected by the failure detection unit. The motor turns on measuring the voltage values of the plurality of battery cells by a voltage sensor wherein the contactor, and performs charge and discharge control of the battery unit on the basis of the measured value.

  According to a second aspect of the present invention, in the charge control device for a vehicle according to the first aspect, when a failure of the cell voltage sensor is further detected, the control means turns on the charging contactor and the vehicle has a predetermined vehicle speed. It is characterized in that it is performed only while traveling.

  The invention according to claim 3 is the charge control device for a vehicle according to claim 1 or 2, wherein the control means is normal when a failure of the cell voltage sensor is detected and the charge contactor is turned on. The normal measured value of the cell voltage sensor whose failure is detected is estimated by the measured value of the cell voltage sensor and the total voltage value of the plurality of battery cells measured by the contactor voltage sensor, and the estimated value is estimated. The charge and discharge control is performed on the basis of

  The invention according to claim 4 is the charge control device for a vehicle according to any one of claims 1 to 3, wherein the control means further includes a resistance value of the charging contactor and a resistance value of the charging circuit. The charge and discharge control is performed based on the above.

  According to the present invention, it is possible to safely drive the vehicle even when the voltage sensor fails, and to prevent the failure of the battery cell due to the occurrence of overcharge or overdischarge.

It is the schematic of the charge control apparatus of the vehicle used for one Embodiment of this invention. It is a control block diagram of ECU used for one embodiment of the present invention. It is a flowchart explaining the operation | movement in one Embodiment of this invention.

  FIG. 1 is a schematic view showing a charge control device of a vehicle used in an embodiment of the present invention. The vehicle to which the present invention can be applied is an electric vehicle or a plug-in hybrid vehicle provided with the quick charging connector 1. A quick charging connector 1 as a charging connector is provided on a vehicle body (not shown), and a quick charging plug is attached when the quick charging is performed. The quick charge contactor 2 is connected to the quick charge connector 1, and the quick charge contactor 2 is turned on when the quick charge plug is attached to the quick charge connector 1. The rapid charging contactor 2 is connected to the battery assembly 3, and the battery assembly 3 supplies power to the high voltage load 4 based on the drive of a motor or an inverter of the vehicle.

  The battery assembly 3 is configured by arranging the battery unit 5, and the battery unit 5 is configured by a unit battery called a cell 6 which is a plurality of battery cells. Each cell 6 can be charged to a predetermined voltage, and a value (400 V) obtained by multiplying the predetermined voltage (for example, 5 V) by the number of cells (for example, 80 cells) is the total voltage of the battery unit 5. Each cell 6 is connected to a battery voltage sensor 7 as a cell voltage sensor that detects the voltage of each cell 6. Further, a plurality of battery contactors 8 and current sensors 9 are connected to the battery assembly 3 for performing charge / discharge control of the battery unit 5 connected to the battery unit 5. Further, a failure detection voltage sensor 10 for the rapid charging contactor 2 which is a contactor voltage sensor, which is a feature of the present invention, is disposed inside the battery assembly 3. The failure detection voltage sensor 10 is connected to the terminal of the rapid charging contactor 2, and measures the voltage when the rapid charging contactor 2 is turned on and closed.

  FIG. 2 is a block diagram of an ECU, which is control means for performing charge / discharge control of the battery unit 5 in the charge control device for a vehicle shown in FIG. 1, used in one embodiment of the present invention. An ECU 11 formed of a known microcomputer having a CPU, a ROM, a RAM and the like (not shown) is provided on a vehicle body (not shown). In addition to the quick charge contactor 2, the battery voltage sensors 7, the battery contactors 8, and the failure detection voltage sensor 10 described above in the ECU 11, a vehicle speed for determining whether the vehicle is running or stopped. A sensor 12 is connected.

The operation of the present invention in the above-described configuration will be described based on the flowchart shown in FIG.
First, when the ECU 11 determines that the battery voltage sensor 7 is faulty (ST01), it determines whether the vehicle is traveling based on the information from the vehicle speed sensor 12 (ST02). The determination as to whether or not the battery voltage sensor 7 is in failure regards the battery voltage sensor 7 corresponding to the unreached cell 6 as failure if the voltage of each cell 6 has not reached the set value. Here, it is determined that one battery voltage sensor 7 has a failure. When the vehicle is traveling, the ECU 11 sends an operation command to the rapid charging contactor 2 and forcibly turns it on (ST03). When the quick charge contactor 2 is turned on, the fault detection voltage sensor 10 can detect the total voltage of the battery pack 3, and the ECU 11 reads the total voltage (ST04) and each battery voltage sensor 7 measures each voltage. The voltage of the cell 6 is read (ST05).

  Next, the ECU 11 estimates the total voltage of the battery pack 3 from the total voltage read (here, the total voltage read = the estimated total voltage of the battery pack 3). Then, the ECU 11 performs charge and discharge control of the battery unit 5 based on the estimated total voltage value. Specifically, the ECU 11 subtracts the sum of the voltages measured by the respective battery voltage sensors 7 from the estimated total voltage. For example, when the estimated total voltage is 400 V and the measured total voltage which is the sum of the voltages measured by the respective battery voltage sensors 7 is 395 V, the measured total voltage is 5 V insufficient with respect to the estimated total voltage. The normal measurement value in the case where the cell 6 corresponding to the battery voltage sensor 7 is measured normally can be estimated to be 5 V (ST06). As described above, when the battery voltage sensor 7 is broken, the ECU 11 performs charge / discharge control of the battery unit 5 by adding 5 V of the normal measurement value estimated to the measured total voltage (ST 07). Individual charge / discharge control is performed on each cell 6 based on the estimated normal measurement value and the actual measurement value of the battery voltage sensor 7 in which a failure is not detected. Further, a display (not shown) displays that there is an abnormality in the battery pack 3. As a result, when the driver's fault is reported to the driver and the driver goes to the dealer, the occurrence of overcharge and overdischarge is prevented by the ECU 11 performing charge / discharge control, and the driver can run the vehicle safely. Can.

  In the above embodiment, when a plurality of battery voltage sensors 7 corresponding to each cell 6 fail, the ECU 11 performs charge / discharge control in consideration of safety according to the number. For example, when it is determined that the six battery voltage sensors 7 are broken at a measured total voltage of 370 V, the ECU 11 may have 3 to 4 V which is about 60 to 80% of 5 V for each of the 80 cells 6 Control charge and discharge so that it becomes the voltage of That is, charge and discharge control is performed such that the total voltage is 240 V to 320 V, which is 60 to 80% of 400 V. Thereby, each cell 6 can be reliably prevented from being overcharged.

  Next, the ECU 11 determines whether the vehicle has stopped based on the information from the vehicle speed sensor 12 (ST08). When it is determined that the vehicle has completely stopped, the quick charge contactor 2 is turned off (ST09) to complete a series of operations.

  According to the above configuration, when the battery voltage sensor 7 breaks down, the ECU 11 turns on the rapid charging contactor 2 to estimate the total voltage value, and performs charge / discharge control of the battery unit 5 based on the estimated value. As a result, the occurrence of overcharge and overdischarge can be prevented to allow the vehicle to travel safely, and failure of the battery unit 5 can be prevented.

  Further, according to the above configuration, the normal measurement value of the cell 6 corresponding to the battery voltage sensor 7 in which the failure is detected is estimated, and the estimated normal measurement value and the actual measurement value of the battery voltage sensor 7 in which the failure is not detected Since individual charge and discharge control can be performed on each cell 6, it is possible to prevent the decrease in accuracy of the charge and discharge control even at the time of failure of the battery voltage sensor 7.

  In the above embodiment, the quick charge contactor 2 is turned on when the vehicle is simply traveling in step ST03 of FIG. 3, but when the vehicle is moving at a low speed, the rapid charge contactor 2 is used. There is a possibility that an electric shock may occur due to the accidental contact. Therefore, according to a modification of the present invention, the rapid charging contactor 2 is turned on only while the vehicle is traveling at a predetermined vehicle speed, for example, at a speed of 20 km / h or more, thereby reliably generating the above-mentioned problems. It can be prevented.

  In the said embodiment, the example which ECU11 performs charge / discharge control of the battery unit 5 was shown, without considering the resistance value of the contactor 2 for rapid charging, and the resistance value of a charging circuit. However, the resistance value of the rapid charging contactor 2 and the resistance value of the charging circuit are each measured in advance, and the ECU 11 performs charge / discharge control of the battery unit 5 after applying corrections in consideration of this. Accurate charge and discharge control can be performed.

  Specifically, although the measurement value measured by the failure detection voltage sensor 10 is estimated as the total voltage of the assembled battery 3 in the above embodiment, the present invention is not limited to this, and for the measurement value measured by the failure detection voltage sensor 10 A correction may be made according to the resistance value of the rapid charging contactor 2 and the resistance value of the charging circuit, and the value after the correction may be estimated as the total voltage of the assembled battery 3. As a result, the occurrence of overcharge and overdischarge can be further prevented to allow the vehicle to travel safely, and failure of the battery unit 5 can be reliably prevented.

  Although the example which applied the charging device of the vehicle to the rapid-charging circuit was shown in the said embodiment, this invention is not limited to this, It is also possible to apply to a normal charging circuit. When applied to a normal charging circuit, the charging device of the vehicle includes a normal charging port on the vehicle side to which a charging connector connected to an external power supply can be connected, and a normal charging for connecting between the normal charging port and a plurality of battery cells A contactor for normal charging that switches between the circuit and the normal charging circuit in a disconnected state and a connected state, a voltage sensor for a contactor used for detecting a failure in a contact for normal charging, and corresponding to each battery cell A plurality of cell voltage sensors for measuring the voltage of the battery cell, failure detection means for detecting a failure of each cell voltage sensor, and control means for performing charge and discharge control of the battery unit are provided.

  Furthermore, a power converter for converting an alternating current into a direct current is provided between the normal charging port and the plurality of battery cells. Therefore, when the failure of the cell voltage sensor is detected, the normal charging contactor is turned on to estimate the voltage values of the plurality of battery cells by the contactor voltage sensor, the voltage applied to the power conversion device is It needs to be considered. On the other hand, in the case of a rapid charging circuit, since a power conversion device is not interposed on the circuit, when a failure of the cell voltage sensor is detected, the voltage value of the battery cell can be easily estimated by the contactor voltage sensor. it can.

  In the said embodiment, only one ECU 11 which functions as a control means was shown. However, in the embodiment of the present invention, a plurality of ECUs functioning as control means may be provided, for example, an ECU in an assembled battery, an ECU in a charger system, etc. The number of ECUs is not limited to one.

  As mentioned above, although the preferable embodiment of this invention was described, this invention is not limited to the specific embodiment mentioned above, Unless it specifically limited by the above-mentioned description, it stated in the claim. Various modifications and changes are possible within the scope of the present invention. The effects described in the embodiments of the present invention only list the most preferable effects resulting from the present invention, and the effects according to the present invention are not limited to those described in the embodiments of the present invention. .

DESCRIPTION OF SYMBOLS 1 ... charge connector (connector for quick charge), 2 ... contactor for quick charge, 5 ... battery unit, 6 ... cell (battery cell), 7 ... voltage sensor for cells (battery voltage Sensor), 10 ... Voltage sensor for contactor (voltage sensor for failure detection), 11 ... Control means (ECU)

Claims (4)

A plurality of battery cells constituting an on-vehicle battery unit, a vehicle-side charge port to which a charge connector connected to an external power source can be connected, and a charge circuit connecting the charge port and each battery cell; The charging contactor for switching between the blocking state and the connection state of the charging circuit, the contactor voltage sensor used for detecting the failure of the charging contactor, and the battery cell provided corresponding to each of the battery cells A plurality of cell voltage sensors for measuring the voltage of the battery, failure detection means for detecting a failure of each of the cell voltage sensors, and control means for performing charge / discharge control of the battery unit,
The control means turns on the charging contactor so that the charging circuit is in a connected state when the failure detection means detects a failure in any of the cell voltage sensors, and the contactor voltage sensor detects the failure. A charge control device for a vehicle, which measures voltage values of the plurality of battery cells and performs charge / discharge control of the battery unit based on the measured values. In the vehicle charge control device according to claim 1,
A charge control device for a vehicle, wherein the control means turns on the charging contactor only when the vehicle is traveling at a predetermined vehicle speed or more when a failure of the cell voltage sensor is detected. In the vehicle charge control device according to claim 1 or 2,
When the control unit detects a failure of the cell voltage sensor and turns on the charging contactor, the plurality of battery cells are measured by the measurement value of the normal cell voltage sensor and the contactor voltage sensor. A charge control device for a vehicle, comprising: estimating a normal measurement value of the cell voltage sensor in which a failure is detected from the total voltage value of and the charge / discharge control based on the estimation value. The charge control device for a vehicle according to any one of claims 1 to 3.
The charge control device for a vehicle, wherein the control means further performs the charge and discharge control based on a resistance value of the charging contactor and a resistance value of a charging circuit.

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