JP2018038130A - Electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To retain the state of no electric charge remaining in a charging device used for external charging while suppressing the frequency of starting the charging device in an electric vehicle that includes the device.SOLUTION: In an electric vehicle including a charging device for external charging, a vehicle ECU stores an immediate-post-stop flag on internal memory as charging device activation history information, where the aforementioned flag shows whether elapsed time (post-immediate-past stop time) from a most recent stop clock-time of the charging device to the present time is less than a certain period of time. In the case of a user requesting a vehicle start, and in a case where the immediate-post-stop flag stored in internal memory of the vehicle ECU is On (meaning that the post-immediate-past stop time is less than the certain period of time), the vehicle ECU determines that electric charge remain in the charging device, thus starting the device to discharge the remaining electric charge. Whereas if the immediate-post-stop flag is Off, the vehicle ECU determines no electric charge remaining in the charging device, hence not starting the device.SELECTED DRAWING: Figure 4

Description

  The present disclosure relates to an electric vehicle including a charger for external charging.

  Japanese Patent Laid-Open No. 2013-55800 (Patent Document 1) is supplied from a driving battery, a driving device (such as a motor) that generates vehicle driving force using electric power stored in the driving battery, and an external power source. There is disclosed an electric vehicle including a charger for charging a driving battery using electric power (hereinafter also referred to as “external charging”). The charger is configured to start in response to receiving an activation signal from the outside and perform external charging in a state where the driving device is disconnected from the driving battery (Ready-OFF state).

JP2013-55800A

  Generally, a charger mounted on an electric vehicle is provided with a smoothing capacitor. During external charging, a charge is accumulated in the capacitor in the charger. Since there is a concern about vehicle collision while the vehicle is traveling, it is desirable to discharge the electric charge accumulated in the capacitor during external charging (hereinafter also referred to as “remaining charge in the charger”) before traveling the vehicle.

  As a method of discharging the remaining charge in the charger before traveling the vehicle, for example, every time there is a vehicle start request (start request for driving device) by the user, the charger is started, and the remaining charge in the charger is It is conceivable to operate the charger so as to discharge. However, if the charger is activated every time there is a vehicle activation request, the charger is frequently activated at a timing that does not require external charging, and there is a concern that the charger will deteriorate early.

  The present disclosure has been made in order to solve the above-described problems, and an object of the present disclosure is to reduce residual frequency in a charger while suppressing the frequency of activation of the charger in an electric vehicle including a charger for external charging. This is to ensure that there is no state.

  An electric vehicle according to the present disclosure is an electric vehicle that can be connected to an external power source, and is supplied from a driving battery, a driving device that generates a vehicle driving force using electric power stored in the driving battery, and an external power source. A battery charger for charging the drive battery using electric power and a vehicle control unit for controlling the drive device and the battery charger. The vehicle control unit stores the operation history information of the charger. The vehicle control unit determines whether or not there is a remaining charge in the charger from the stored operation history information of the charger when there is a drive activation request, and maintains the charger in a stopped state when there is no remaining charge. When the remaining charge is present, the charger is activated to operate the charger so as to discharge the remaining charge.

  According to the above configuration, the vehicle control unit determines whether or not there is a residual charge in the charger from the operation history information of the charger stored in the vehicle control unit when the drive device is requested to start. The vehicle control unit activates the charger to discharge the remaining charge when there is a remaining charge, and does not activate the charger when there is no remaining charge. Thereby, compared with the case where a charger is started each time there is a vehicle activation request, it is possible to secure a state where there is no residual charge in the charger while suppressing the activation frequency of the charger.

It is a figure which shows typically the whole structure of an electric vehicle. It is a figure which shows typically an example of a process of vehicle ECU and a charger. It is a flowchart (the 1) which shows an example of the process sequence of vehicle ECU. It is a flowchart (the 2) which shows an example of the process sequence of vehicle ECU. FIG. 3 is a diagram (part 1) illustrating an example of operations of a vehicle ECU and a charger. FIG. 8 is a second diagram illustrating an example of operations of the vehicle ECU and the charger.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Overall configuration>
FIG. 1 is a diagram schematically showing an overall configuration of an electric vehicle 1 according to the present embodiment. The electric vehicle 1 includes a drive device 10, a battery (drive battery) 20, a system main relay 21, a charge relay 22, a charger 30, a connector 40, and a vehicle control unit (hereinafter referred to as “vehicle ECU” (ECU : Electronic Control Unit) 100).

  The electric vehicle 1 travels with the driving force generated by the driving device 10. The electric vehicle 1 may be configured to travel using the power of an engine (not shown) in addition to the driving force generated by the driving device 10.

  The driving device 10 generates vehicle driving force using electric power supplied from the battery 20. Drive device 10 includes a motor generator mechanically connected to the drive wheels, and a power control unit (such as an inverter) that controls the amount of power supplied to the motor generator. The output of drive device 10 (the amount of power supplied to the motor generator) is controlled by a control signal from vehicle ECU 100. Note that the number of motor generators included in the driving apparatus 10 may be one or two or more.

  The battery 20 is a rechargeable power storage device, for example, a secondary battery such as a nickel metal hydride battery or a lithium ion battery. The battery 20 is connected to the drive device 10 via the system main relay 21.

  System main relay 21 is provided between drive device 10 and battery 20 and is opened and closed by a control signal from vehicle ECU 100. When the system main relay 21 is in the closed state, the driving device 10 is connected to the battery 20 and the driving device 10 is in a state where the driving force can be generated (Ready-ON state). When the system main relay 21 is in the open state, the drive device 10 is disconnected from the battery 20, and the drive device 10 is in a state where it cannot generate a driving force (Ready-OFF state).

  The electric vehicle 1 is configured to be capable of performing “external charging” in which the battery 20 is charged with electric power supplied from an AC power source (hereinafter also referred to as “external power source”) 200 outside the vehicle via the power supply facility 2. The electric vehicle 1 includes a charging relay 22, a charger 30, and a connector 40 as a configuration for performing external charging.

  Charging relay 22 is provided between battery 20 and charger 30 and is opened and closed by a control signal from vehicle ECU 100. The connector 40 is configured to be connectable to the connector 210 of the power supply facility 2.

  The charger 30 is provided between the connector 40 and the charging relay 22, converts alternating current input from the power supply facility 2 into direct current that can charge the battery 20, and converts the converted direct current into the battery via the charging relay 22. 20 output. Specifically, charger 30 includes an AC / DC converter 31, a DC / DC converter 32, a capacitor 33, a voltage sensor 34, a discharge resistor 35, and a charge ECU 36. AC / DC converter 31 and DC / DC converter 32 are connected by positive line PL and negative line NL.

  The AC / DC converter 31 converts (rectifies) the alternating current input from the power supply facility 2 into direct current based on the drive signal from the charging ECU 36 and outputs the direct current to the positive line PL and the negative line NL. Further, the AC / DC converter 31 also operates as a power factor correction (PFC) circuit that improves the power factor by bringing the AC power input from the power supply facility 2 closer to a sine wave.

  The DC / DC converter 32 converts the output voltage of the AC / DC converter 31 into the voltage of the battery 20 based on the drive signal from the charging ECU 36 and outputs the voltage to the battery 20. The DC / DC converter 32 is a so-called insulated DC / DC converter.

  Capacitor 33 has one end connected to positive line PL and the other end connected to negative line NL, and smoothes the voltage between positive line PL and negative line NL.

  Voltage sensor 34 detects a voltage between positive electrode line PL and negative electrode line NL (that is, a voltage across capacitor 33, hereinafter also referred to as “voltage VH”), and outputs the detection result to charging ECU 36.

  Discharge resistor 35 has one end connected to positive line PL and the other end connected to negative line NL. The electric charge accumulated in the capacitor 33 in the charger 30 during external charging (hereinafter also referred to as “residual electric charge in the charger 30”) is gradually reduced by the discharge resistor 35 after external charging, and a certain time Tth (for example, 5th) It becomes zero after a minute). In other words, it takes a certain time Tth to discharge the remaining charge in the charger 30 by the discharge resistor 35.

  The charging ECU 36 includes a CPU (Central Processing Unit) (not shown). Charging ECU 36 controls driving of AC / DC conversion unit 31 and DC / DC conversion unit 32 based on a control signal from vehicle ECU 100.

  The vehicle ECU 100 incorporates a CPU and a memory (not shown), and each device (the driving device 10, the system main relay 21, the charging relay 22, the charging device 10) of the electric vehicle 1 based on information stored in the memory and information from each sensor. The device 30).

  For example, the vehicle ECU 100 switches the system main relay 21 from the open state to the closed state when there is a vehicle start request (start request for the drive device 10) by the user in the Ready-OFF state. As a result, the drive device 10 enters a Ready-ON state in which a drive force can be generated.

  The power supply facility 2 includes a connector 210, a CCID (Charging Circuit Interrupt Device) relay 220, and a facility ECU 230. The CCID relay 220 is provided on an energization path that connects the external power source 200 and the connector 210. When the CCID relay 220 is in the open state, the energization path from the external power source 200 to the connector 210 is interrupted. On the other hand, when the CCID relay 220 is in a closed state, an energization path from the external power source 200 to the connector 210 is formed.

  The facility ECU 230 is configured to be able to communicate with the vehicle ECU 100 of the electric vehicle 1 in a state where the connector 210 of the power supply facility 2 is connected to the connector 40 of the electric vehicle 1 (hereinafter also referred to as “plug-in state”). The equipment ECU 230 closes the CCID relay 220 in response to receiving a CCID connection request from the vehicle ECU 100 in the plug-in state. Thereby, the voltage from the external power supply 200 is applied to the charger 30 of the electric vehicle 1.

<External charging control>
The user can start external charging by performing an operation (hereinafter also referred to as “plug-in operation”) for connecting the connector 210 of the power supply facility 2 to the connector 40 of the electric vehicle 1 in the Ready-OFF state.

  When the vehicle ECU 100 detects that the user has performed the plug-in operation in the Ready-OFF state, the vehicle ECU 100 closes the charging relay 22 and outputs a CCID connection request to the facility ECU 230 of the power supply facility 2. An external charging request is output to 30 charging ECUs 36.

  As described above, the facility ECU 230 closes the CCID relay 220 in response to receiving the CCID connection request from the vehicle ECU 100. Thereby, the voltage from the external power supply 200 is applied to the charger 30 of the electric vehicle 1.

  The charger 30 is activated in response to receiving an external charging request from the vehicle ECU 100. The activation of the charger 30 refers to switching from a stopped state (power-off state) where operating power is not supplied to the charging ECU 36 from an auxiliary battery (not shown) to an operating state (power-on state) where operating power is supplied. means.

  The charger 30 controls driving of the AC / DC conversion unit 31 and the DC / DC conversion unit 32 based on a control signal from the vehicle ECU 100 after activation. Thereby, external charging is performed.

  When the external charging request from the vehicle ECU 100 is stopped along with the completion of the external charging, the charger 30 is switched to a stopped state (power off state). Thereby, it is suppressed that the power of the auxiliary battery is unnecessarily consumed by the standby current of the charger 30.

<Charger discharge control>
During external charging, electric charge accumulates in the capacitor 33 in the charger 30. Since there is a concern about a vehicle collision while the electric vehicle 1 is traveling, it is desirable to discharge the remaining charge in the charger 30 (charge accumulated in the capacitor 33 during external charging) before the start of traveling.

  The charger 30 according to the present embodiment is provided with a discharge resistor 35 for discharging the remaining charge in the charger 30. However, as described above, it takes a certain time Tth to discharge the remaining charge in the charger 30 by the discharge resistor 35. Therefore, for example, if there is a vehicle activation request after a certain time Tth has elapsed after the completion of external charging, traveling can be started with charge remaining in the charger 30. That is, with the discharge resistor 35 alone, there may occur a situation where the remaining charge in the charger 30 cannot be discharged before the start of traveling. Therefore, it is necessary to discharge the remaining charge in the charger 30 more reliably before the start of traveling.

  As a method of discharging the remaining charge in the charger 30 more reliably before the start of traveling, for example, every time there is a vehicle activation request, the charger 30 is activated and the charger 30 is operated so as to discharge the remaining charge ( It is conceivable to drive the AC / DC converter 31 and the DC / DC converter 32). However, if the charger 30 is activated every time there is a vehicle activation request, the charger 30 is frequently activated at a timing that does not require external charging, and there is a concern that the charger 30 may deteriorate early. The

  Therefore, vehicle ECU 100 according to the present embodiment stores operation history information of charger 30 in its own internal memory. Then, when there is a vehicle activation request, the vehicle ECU 100 determines the presence or absence of the remaining charge in the charger 30 from the operation history information of the charger 30 stored in its own internal memory, and according to the determination result Decide whether or not to start the charger 30.

  FIG. 2 is a diagram schematically illustrating an example of processing of the vehicle ECU 100 and the charger 30 when a vehicle activation request is made.

  When there is a vehicle activation request, the vehicle ECU 100 uses the operation history information of the charger 30 stored in its own internal memory to perform “residual charge determination” that determines the presence or absence of the residual charge in the charger 30. Do. When it is determined by the remaining charge determination that there is a remaining charge, the vehicle ECU 100 transmits a charger discharge request to the charger 30.

  Charger 30 is activated in response to receiving a charger discharge request from vehicle ECU 100. The charger 30 performs “discharge control” for driving the AC / DC conversion unit 31 and the DC / DC conversion unit 32 to discharge the remaining charge after activation. When the discharge control is completed, the charger 30 notifies the vehicle ECU 100 of the completion of the discharge control.

  When vehicle ECU 100 receives a notification of completion of discharge control from charger 30, vehicle ECU 100 transmits a charger stop / stop request to charger 30. As a result, the charger 30 enters a stopped state (power off state).

  On the other hand, when it is determined by the remaining charge determination that there is no remaining charge, the vehicle ECU 100 transmits a charger stop request to the charger 30 without transmitting a charger discharge request. Thereby, the charger 30 is maintained in a stopped state without being activated.

  The “operation history information of the charger 30” stored in the vehicle ECU 100 may be information that allows the vehicle ECU 100 to determine the presence or absence of the remaining charge in the charger 30.

  For example, the vehicle ECU 100 can store the closest stop time of the charger 30 from the present time (hereinafter also referred to as “most recent stop time”) in the internal memory as “operation history information of the charger 30”. In this case, when there is a vehicle activation request, the vehicle ECU 100 calculates the elapsed time from the “last stop time” stored in its own internal memory to the present time as the “time after the most recent stop”, and the “last stop” When the “after time” is less than a certain time Tth (the time required for discharging the remaining charge by the discharge resistor 35), it is determined that there is a remaining charge, and when the “time after most recent stop” is equal to or greater than the certain time Tth It can be determined that there is no.

  Further, for example, the vehicle ECU 100 internally uses a flag (hereinafter also referred to as “immediate stop flag”) indicating whether or not the time after the most recent stop is less than a predetermined time Tth as “operation history information of the charger 30”. Can be stored in memory. In this case, in the Ready-OFF state (before the vehicle activation request is made), the vehicle ECU 100 compares in advance the time after the most recent stop with a certain time Tth and stores the result in its own internal memory as a “immediate stop flag”. Remember. Specifically, the ECU 100 turns on the “immediately after stop flag” when the time after the most recent stop is less than the predetermined time Tth, and turns off the “immediately after stop flag” when the time after the most recent stop is equal to or greater than the certain time Tth. To. Then, when the vehicle activation request is made, the vehicle ECU 100 remains when the “immediate stop flag” stored in its own internal memory is on (when the latest stop time is less than the predetermined time Tth). When it is determined that there is a charge and the flag immediately after the stop is OFF (when the time after the latest stop is equal to or longer than a certain time Tth), it can be determined that there is no remaining charge.

  Hereinafter, a case where “operation history information of charger 30” stored in vehicle ECU 100 is set to “immediate stop flag” will be specifically described.

  FIG. 3 is a flowchart illustrating an example of a processing procedure performed by the vehicle ECU 100 when setting the above-described immediately after stop flag on / off. This flowchart is started at predetermined intervals in the Ready-OFF state (before a vehicle activation request is made).

  In step (hereinafter, step is abbreviated as “S”) 10, vehicle ECU 100 determines whether or not charger 30 has been switched from the operating state to the stopped state. For example, vehicle ECU 100 can determine that charger 30 has been switched from the operating state to the stopped state when the CCID connection request changes from on to off.

  When charger 30 is switched from the operating state to the stopped state (YES in S10), vehicle ECU 100 stores the time at which charger 30 is switched from the operating state to the stopped state as the "last stop time" in the internal memory. (S11), and the flag immediately after the stop stored in the internal memory is turned on (S12).

  If charger 30 has not been switched from the operating state to the stopped state (NO in S10), vehicle ECU 100 determines whether or not the flag immediately after stop is in the on state (S14).

  When the flag immediately after the stop is in the on state (YES in S14), vehicle ECU 100 calculates the elapsed time from the latest stop time stored in the internal memory to the present as the “time after the latest stop”, and after the last stop It is determined whether or not the time is less than a certain time Tth (time required for discharging the remaining charge by the discharge resistor 35) (S16).

  If the time after the latest stop is less than the predetermined time Tth (YES in S16), vehicle ECU 100 maintains the immediately after stop flag stored in the internal memory in the on state (S12).

  If the time after the most recent stop is equal to or longer than the predetermined time Tth (NO in S16), vehicle ECU 100 turns off the immediately after stop flag stored in the internal memory (S18).

  FIG. 4 is a flowchart illustrating an example of a processing procedure performed by vehicle ECU 100 when charger 30 performs discharge control. This flowchart is started at predetermined intervals in the Ready-OFF state (before a vehicle activation request is made).

  The vehicle ECU 100 determines whether there is a vehicle activation request from the user (S20). When there is no vehicle activation request (NO in S20), vehicle ECU 100 skips the subsequent processing and ends the processing.

  When there is a vehicle activation request (YES in S20), vehicle ECU 100 determines whether or not the immediately after stop flag stored in its internal memory is on (S22).

  If the flag immediately after the stop is on (YES in S22), vehicle ECU 100 determines that there is a remaining charge in charger 30 (S24), and transmits a charger discharge request to charger 30 (S26). Thereby, the charger 30 is started and the discharge control by the charger 30 is performed.

  On the other hand, when the flag immediately after the stop is in the off state (NO in S22), vehicle ECU 100 determines that there is no remaining charge in charger 30 (S28), and skips the process of S26 to activate charger 30. The process ends without

  FIG. 5 is a diagram illustrating an example of operations of the vehicle ECU 100 and the charger 30 when a vehicle activation request is issued after a predetermined time Tth has elapsed since the completion of external charging.

  When the user performs a plug-in operation at time t <b> 1 in the Ready-OFF state, vehicle ECU 100 outputs an external charging request to charger 30 to activate charger 30. As a result, the external charging control is started and charges are accumulated in the capacitor 33 in the charger 30, so that the voltage VH across the capacitor 33 increases to a predetermined value.

  When external charging is completed at time t2, vehicle ECU 100 stops outputting the external charging request. Thereby, the charger 30 is stopped (power is turned off).

  As shown in FIG. 5, the voltage VH across the capacitor 33 (residual charge in the charger 30) gradually decreases by the discharge function of the discharge resistor 35 after the time t2 when the external charging is completed, and reaches a certain time Tth. It will be zero after the lapse. If vehicle ECU 100 can receive the detected value of voltage VH (the output value of voltage sensor 34) from charging ECU 36, vehicle ECU 100 can determine the presence or absence of residual charge in charger 30 using voltage VH. However, after time t2, charging ECU 36 is stopped, so vehicle ECU 100 cannot receive the detected value of voltage VH (the output value of voltage sensor 34) from charging ECU 36.

  In view of this point, the vehicle ECU 100 stores a flag immediately after the stop in its own internal memory as information for determining the presence or absence of the remaining charge in the charger 30 without starting the charger 30. Specifically, vehicle ECU 100 switches the flag immediately after the stop to the ON state at time t2 when charger 30 is stopped. The vehicle ECU 100 switches the flag immediately after the stop to the OFF state at time t3 when the time after the latest stop (elapsed time from the latest stop time t2) has reached a certain time Tth.

  Thereafter, when there is a vehicle activation request by the user at time t4, the vehicle ECU 100 determines that there is no remaining charge in the charger 30 because the immediately after stop flag stored in its own internal memory is off. Then, no discharge request is output to the charger 30. Therefore, the charger 30 is not activated.

  FIG. 6 is a diagram illustrating an example of operations of the vehicle ECU 100 and the charger 30 when a vehicle activation request is issued before the fixed time Tth has elapsed after completion of external charging.

  When the user performs a plug-in operation at time t11 in the Ready-OFF state, the charger 30 is activated and external charging is started. When external charging is completed at time t12, the charger 30 is stopped (power off). Vehicle ECU 100 switches the flag immediately after the stop to the on state at time t12.

  From the latest stop time t12 to the time t13 when the next vehicle activation request is issued, the time after the latest stop (the elapsed time from the latest stop time t12) is less than the predetermined time Tth, so the vehicle ECU 100 sets the flag immediately after the stop. Keep it on.

  When there is a vehicle activation request at time t13, the vehicle ECU 100 determines that there is a residual charge in the charger 30 because the immediately after stop flag stored in its internal memory is on, and the charger 30 A charger discharge request is output. Thereby, the charger 30 is started and discharge control by the charger 30 is performed.

  When it is confirmed at time t14 that the voltage VH across the capacitor 33 (residual charge in the charger 30) has become zero by the discharge control, the vehicle ECU 100 turns off the flag immediately after stopping and turns off the charger. 30 is stopped.

  As described above, the vehicle ECU 100 according to the present embodiment stores the “immediately after stop flag” indicating whether or not the time after the most recent stop is less than the predetermined time Tth in the internal memory as the operation history information of the charger 30. deep. Then, when there is a vehicle activation request, the vehicle ECU 100 determines whether or not the “immediate stop flag” stored in its own internal memory is on. When the flag immediately after the stop is on (when the time after the most recent stop is less than a certain time Tth), the vehicle ECU 100 determines that there is a residual charge in the charger 30 and activates the charger 30. The remaining charge is discharged. On the other hand, when the flag immediately after the stop is OFF (when the time after the most recent stop is equal to or longer than a certain time Tth), vehicle ECU 100 determines that there is no remaining charge in charger 30 and does not start charger 30. Thereby, compared with the case where the charger 30 is started each time there is a vehicle activation request, it is possible to secure a state where there is no remaining charge in the charger 30 while suppressing the activation frequency of the charger 30.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Electric vehicle, 2 Power supply equipment, 10 Driving device, 20 Battery, 21 System main relay, 22 Charging relay, 30 Charger, 31 AC / DC conversion part, 32 DC / DC conversion part, 33 Capacitor, 34 Voltage sensor, 35 Discharge resistance, 36 Charge ECU, 40, 210 Connector, 100 Vehicle ECU, 200 External power supply, 220 CCID relay, 230 Facility ECU.

Claims (1)

An electric vehicle that can be connected to an external power source,
A battery for driving,
A driving device for generating vehicle driving force using the electric power stored in the driving battery;
A charger for charging the driving battery using electric power supplied from the external power source;
A vehicle control unit for controlling the driving device and the charger;
The vehicle control unit is
Storing operation history information of the charger;
When there is a start request for the driving device, the presence / absence of remaining charge in the charger is determined from the stored operation history information of the charger, and when there is no remaining charge, the charger is maintained in a stopped state. An electric vehicle that activates the charger to discharge the residual charge when the residual charge is present.

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