JP6686802B2 - Electric vehicle - Google Patents

Description

  TECHNICAL FIELD The present invention relates to control of an electric vehicle capable of charging an installed power storage device by receiving power supply from the outside.

  A technique is known in which a power storage device (main battery) mounted on an electric vehicle that uses a motor as a drive source, such as an electric vehicle or a hybrid vehicle, is charged with electric power supplied from outside the vehicle. When such charging is performed, in addition to a high-voltage power storage device that supplies electric power to a drive source, a low-voltage power storage device (auxiliary battery) that supplies power to auxiliary devices mounted on a vehicle. May also be charged.

  For example, Japanese Unexamined Patent Publication No. 2015-212548 (Patent Document 1) discloses a technique of charging an auxiliary battery before charging the main battery when the SOC of the auxiliary battery has not reached a predetermined value. To be done.

Japanese Unexamined Patent Publication No.

  By the way, if the auxiliary battery is also charged while the main battery is being charged when the electric power supplied from the outside is small, the electric power supplied from the outside is also allocated to the charging of the auxiliary battery. In some cases, the charging power for doing so may become small. As a result, when the current flowing through the main battery is reduced to a detection error level, it may not be possible to accurately determine whether the main battery is being charged or discharged. In such a case, it is possible to stop charging using electric power supplied from the outside. However, when the charging using the power supplied from the outside is started in response to the user's request, the charging is not performed in accordance with the user's request, which may deteriorate the convenience.

  The present invention has been made to solve the above-described problems, and an object thereof is to continue charging the main battery even when the electric power supplied from the outside is small and suppress deterioration of convenience. It is to provide an electric vehicle.

  An electric vehicle according to an aspect of the present invention includes a rotating electric machine that is a drive source that drives the vehicle, a first power storage device that supplies electric power to the rotating electric machine, and a second electric power supply that supplies electric power to an auxiliary device mounted on the vehicle. A power storage device; and a first power conversion device for converting AC power from an external power supply provided outside the vehicle into first DC power that can charge the first power storage device and outputting the first DC power to the first power storage device. A second power conversion device for converting the first DC power converted by the first power conversion device into second DC power capable of charging the second power storage device and outputting the second DC power to the second power storage device; A control device that controls the operation of the conversion device and the operation of the second power conversion device is provided. The control device operates the first power conversion device when AC power is supplied from the external power supply to the vehicle, and further when the remaining capacity of the second power storage device is lower than the first threshold value, the second power conversion device. Activate the device. The control device, when the magnitude of the current of the first power storage device is lower than the second threshold value after a predetermined time has elapsed from the start of the operation of the second power conversion device, The operation of the first power conversion device and the second power conversion device is stopped.

  With this configuration, the operation of the first power conversion device and the second power conversion device is continued until the predetermined time elapses after the operation of the second power conversion device is started. 1 It is possible to continue charging the power storage device. Therefore, when the charging of the first power storage device is started in response to the user's request, the charging in accordance with the user's request can be continued, so that the deterioration of convenience can be suppressed. On the other hand, when the magnitude of the current of the first power storage device is smaller than the second threshold value after the elapse of the predetermined time, the charging of the first power storage device is stopped. Therefore, it is possible to prevent the state where it is difficult to clearly determine whether the battery is being charged or discharged from continuing. Therefore, it is possible to prevent the first power storage device from being overcharged or overdischarged.

  According to the present invention, it is possible to provide an electric vehicle that continues charging the main battery and suppresses deterioration of convenience even when the electric power supplied from the outside is small.

FIG. 1 is a block diagram schematically showing an overall configuration of an electric vehicle according to this embodiment. FIG. 9 is a diagram showing a breakdown of consumption destinations on the vehicle side of input power from an external power supply during normal charging and when charging power is small. 5 is a flowchart showing a control process executed by the ECU in the present embodiment. 3 is a timing chart for explaining the operation of the ECU in the present embodiment. It is a block diagram which shows schematically the whole structure of the electric vehicle which concerns on a modification. 8 is a timing chart for explaining the operation of the ECU in the modified example.

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

  FIG. 1 is a block diagram schematically showing an overall configuration of an electric vehicle 1 (hereinafter simply referred to as vehicle 1) according to the present embodiment. As shown in FIG. 1, the vehicle 1 includes an electric load 10, a charging device 20, a main battery 30, a DC / DC converter 40, an auxiliary battery 50, a charging relay 60, an inlet 70, an ECU ( Electronic Control Unit) 100.

  The electric load 10 includes a motor generator (hereinafter, referred to as MG) 12 and a PCU (Power Control Unit) 14 that exchanges electric power with the MG 12.

  MG 12 is a rotary electric machine that is a drive source that drives vehicle 1, and is, for example, a three-phase AC rotary electric machine. MG 12 is connected to drive wheels (not shown) and has a function as a motor for driving the drive wheels and a function as a generator for performing regenerative braking. The PCU 14 may be configured to include, for example, an inverter and a converter, or may be configured by a single inverter.

  The charging device 20 converts AC power supplied from the external power supply 160 into DC power that can charge the main battery 30, and outputs the converted DC power to the main battery 30, or alternatively, the main battery 30 and the DC. It outputs to both of the / DC converter 40. Charging device 20 uses main battery 30 with electric power supplied from external power supply 160 in response to a control signal from ECU 100 when charging plug 150 is attached to inlet 70 of vehicle 1 while vehicle 1 is stopped, for example. To charge.

  The charging plug 150 is connected to one end of the charging cable 152. The other end of charging cable 152 is connected to external power supply 160. External power supply 160 is an AC power supply, and is, for example, a commercial power supply. It should be noted that the present embodiment will be described on the premise that a charging method in which electric power is supplied from external power supply 160 to main battery 30 of vehicle 1 by contact power supply using charging plug 150 or the like is used. In addition to or instead of the above, a charging method in which electric power is supplied from the external power supply 160 to the main battery 30 of the vehicle 1 by contactless power supply such as a resonance method or electromagnetic induction may be used.

  The main battery 30 is a power storage device and is a rechargeable DC power supply. As the main battery 30, for example, a secondary battery such as a nickel hydrogen battery or a lithium ion battery is used. The voltage of the main battery 30 is, for example, about 200V. Main battery 30 is charged using electric power generated by MG 12, and is also charged using electric power supplied from external power supply 160. The main battery 30 is not limited to the secondary battery, and may be a battery that can generate a DC voltage, such as a capacitor.

  The DC / DC converter 40, for example, when the charging relay 60 is in the ON state, responds to the control signal from the ECU 100 with the DC power output from the charging device 20 to charge the auxiliary battery 50. And output to the auxiliary battery 50.

  Auxiliary battery 50 is a power storage device that supplies electric power to an auxiliary device mounted on vehicle 1. The auxiliary device mounted on the vehicle 1 refers to, for example, an electric device other than the electric device powered by the main battery 30 among the electric devices mounted on the vehicle 1. The auxiliary battery 50 is, for example, a secondary battery such as lead storage having a predetermined output voltage (for example, 12 V).

  The charging relay 60 electrically connects the charging device 20 and the DC / DC converter 40 (ON state) or cuts them (OFF state) according to a control signal from the ECU 100. The ECU 100 turns on the charging relay 60 when the voltage of the auxiliary battery 50 drops below a threshold value while charging the main battery 30 using the external power supply 160, and the DC / DC converter 40, for example. Is operated to charge the auxiliary battery 50.

  The current sensor 102 detects the current IB of the main battery 30. Specifically, current sensor 102 detects current IB that branches from the power line connecting charging device 20 and charging relay 60 and flows through the power line connected to main battery 30. The current sensor 102 transmits a signal indicating the detected current IB to the ECU 100.

  Although not shown, the ECU 100 is configured to include a CPU (Central Processing Unit), a memory that is a storage device, an input / output buffer, and the like. The ECU 100 controls various devices so that the vehicle 1 is in a desired state based on signals from various sensors and devices such as the current sensor 102, and maps and programs stored in the memory. Note that various controls are not limited to the processing by software, and may be processed by dedicated hardware (electronic circuit).

  The ECU 100 controls the operation of the electric load 10, the charging device 20, the charging relay 60, the DC / DC converter 40, and the like to drive the vehicle 1 or charge the main battery 30 or the auxiliary battery 50. Is a control device for.

  The ECU 100 operates the charging device 20 to charge the main battery 30 when the charging plug 150 is connected to the inlet 70, for example. When the charging plug 150 is connected to the inlet 70, the ECU 100 may start charging the main battery 30 at the time when the charging plug 150 is connected, or when the time to start charging is set by the user. In addition, the charging of the main battery 30 may be started at the time when the set time is reached. The ECU 100 may determine whether or not the charging plug 150 is connected to the inlet 70 by using, for example, a contact sensor provided in the inlet 70, or by connecting the charging plug 150 to the inlet 70. It may be determined whether or not the charging plug 150 is connected to the inlet 70 using an electric circuit in which the voltage output to the ECU 100 changes.

  The ECU 100 also estimates the remaining capacity of the main battery 30 (hereinafter, referred to as SOC (State Of Charge)). ECU 200 may estimate the SOC of main battery 30 by integrating the charging current and the discharging current of main battery 30, for example. Alternatively, the ECU 100 estimates OCV (Open Circuit Voltage) based on the current IB of the main battery 30, the voltage between the terminals of the main battery 30, and the temperature of the main battery 30, and the estimated OCV and the predetermined OCV are determined, for example. The SOC of the main battery 30 may be estimated based on the above map. Further, ECU 100 estimates the SOC of auxiliary battery 50. ECU 100 may estimate the SOC of auxiliary battery 50 based on the voltage of auxiliary battery 50 and a predetermined map, for example.

  In the vehicle 1 having the above-mentioned configuration, when the power supplied from the outside is small at the time of charging using the external power supply 160, if the auxiliary battery 50 is also charged while the main battery 30 is being charged, Since the electric power supplied from the battery is also allocated to charge the auxiliary battery 50, the charging power for charging the main battery 30 may be small.

  FIG. 2 is a diagram showing a breakdown of consumption destinations on the vehicle 1 side of the input power from the external power supply 160 during normal charging and when charging power is small. FIG. 2 shows a breakdown of consumers at a certain time point after the start of external charging. As shown in FIG. 2, when the auxiliary battery 50 is charged, the sum of the electric power consumed by the operation of the auxiliary device, the electric power consumed by the charging of the auxiliary battery 50, and the electric power consumed by the loss Is almost unchanged, the charging power of the main battery 30 is small when the charging power is small.

  As shown in FIG. 2, when the charging power of the main battery 30 becomes smaller and falls below the threshold value shown by the broken line in FIG. 2, the current IB of the main battery 30 may become as small as a detection error. In this case, the ECU 100 may not be able to accurately determine whether the main battery 30 is being charged or discharged from the value of the current IB detected by the current sensor 102.

  In such a case, it may be possible to stop the charging using the power supplied from the outside, but if the charging using the power supplied from the outside is started in response to the user's request, the charging of the user Even if there is a request, charging will not be performed, and convenience may deteriorate.

  Therefore, in the present embodiment, ECU 100 operates charging device 20 when the AC power is supplied from external power supply 160 to vehicle 1, and the SOC of auxiliary battery 50 is lower than the first threshold value. At times, the DC / DC converter 40 is operated. Then, when the magnitude of current IB falls below the second threshold value after a predetermined time has elapsed from the start of operation of DC / DC converter 40, ECU 100 causes charging device 20 and The operation of the DC / DC converter 40 is stopped.

  In this way, the main battery 30 can be operated by continuing the operations of the charging device 20 and the DC / DC converter 40 until the predetermined time elapses after the operation of the DC / DC converter 40 is started. Can continue to be charged. On the other hand, when the magnitude of the current IB of the main battery 30 is smaller than the second threshold value after the elapse of the predetermined time, the charging of the main battery 30 is stopped. Therefore, it is possible to prevent the state where it is difficult to clearly determine whether the main battery 30 is being charged or discharged from continuing.

  FIG. 3 is a flowchart showing a control process executed by ECU 100 in the present embodiment.

  In step (hereinafter, referred to as “S”) 100, ECU 100 determines whether external charging is being performed. For example, ECU 100 determines that external charging is in progress when charging plug 150 is attached to inlet 70 and charging device 20 is in operation. If it is determined that external charging is being performed (YES in S100), the process proceeds to S102.

  In S102, ECU 100 determines whether or not the SOC of auxiliary battery 50 is decreasing. Specifically, ECU 100 determines that the SOC of auxiliary battery 50 is decreasing when the SOC of auxiliary battery 50 is equal to or lower than the first threshold value. If it is determined that the SOC of auxiliary battery 50 is decreasing (YES in S102), the process proceeds to S104.

  In S104, ECU 100 turns on charging relay 60. In S106, ECU 100 operates DC / DC converter 40. The auxiliary battery 50 is charged by the operation of the DC / DC converter 40.

  In S108, ECU 100 determines whether or not a predetermined time has elapsed since the operation of DC / DC converter 40 was started. For example, the predetermined time is set to be longer than the time from the start of charging of auxiliary battery 50 until the reduction in the charging power of main battery 30 is resolved. The ECU 100 turns on the stop suppression flag when it is determined that the predetermined time has not elapsed, for example. The ECU 100 turns off the stop suppression flag, for example, when it is determined that the predetermined time has elapsed. If it is determined that the predetermined time has elapsed (YES in S108), the process proceeds to S110.

  In S110, ECU 100 determines whether or not the magnitude of current IB of main battery 30 is decreasing. Specifically, ECU 100 determines that the magnitude of current IB of the main battery has decreased when the magnitude of current IB is equal to or less than the second threshold value. If it is determined that the magnitude of current IB has decreased (YES in S110), the process proceeds to S112.

  In S112, ECU 100 stops the operations of charging device 20 and DC / DC converter 40. The ECU 100 operates the charging device 20 and the DC / DC converter 40 when the stop suppression flag is off and the magnitude of the current IB of the main battery 30 is equal to or less than the second threshold value, for example. Stop.

  On the other hand, if it is determined that the predetermined time has not elapsed (NO in S108) or if the magnitude of current IB has not decreased (NO in S110), the process is It moves to S114. In S114, ECU 100 continues the operations of charging device 20 and DC / DC converter 40. For example, when the stop suppression flag is in the ON state, ECU 100 operates the charging device 20 and the DC / DC converter 40 even if the magnitude of the current IB of the main battery 30 is equal to or less than the second threshold value. continue. Further, ECU 100 continues the operation of charging device 20 and DC / DC converter 40, for example, when the magnitude of current IB of main battery 30 is larger than the second threshold value.

  If it is determined that external charging is not being performed (NO in S100), or if it is determined that the SOC of auxiliary battery 50 has not decreased (NO in S102), ECU 100 ends this processing. To do.

  The operation of ECU 100 in the present embodiment based on the structure and flowchart as described above will be described with reference to FIG. FIG. 4 is a timing chart for explaining the operation of ECU 100 in the present embodiment. The timing chart shown in FIG. 4 is premised on, for example, a case where external charging is being performed and the SOC of auxiliary battery 50 has not decreased.

  LN1 in FIG. 4 indicates a change in charging power of the main battery 30. LN2 in FIG. 4 indicates a change in the command voltage of the auxiliary battery 50. LN3 in FIG. 4 indicates a change in the stop suppression flag. LN4 in FIG. 4 indicates a change in the operating state of the DC / DC converter 40. The horizontal axis of FIG. 4 represents time.

  As shown by LN1 in FIG. 4, it is assumed, for example, that the charging power of main battery 30 is PB (0) higher than the threshold value PB corresponding to the second threshold value of the charging current. Further, it is assumed that the command voltage of auxiliary battery 50 is VA (1) as indicated by LN2 in FIG. 4 and the stop suppression flag is in the off state as indicated by LN3 in FIG. Further, as indicated by LN4 in FIG. 4, the DC / DC converter 40 is assumed to be in a stopped state (off state). At this time, the charging relay 60 is in a cutoff state (off state).

  During external charging (YES in S100), if the SOC of auxiliary battery 50 is higher than the first threshold value (NO in S102), auxiliary battery 50 is not charged, and therefore DC / The state where the DC converter 40 does not operate continues.

  On the other hand, at time t (0), when the SOC of auxiliary battery 50 falls below the first threshold value (YES in S102), charging relay 60 is turned on (S104), and DC is generated. The operation of the / DC converter 40 is started (S106). The operation of the DC / DC converter 40 is started, and the command voltage of the auxiliary battery 50 rises from VA (1) to VA (0). Therefore, a part of the input power from external power supply 160 is allocated to charge auxiliary battery 50, so that the charging power of main battery 30 decreases from PB (0) to PB (1) lower than threshold value PB. . During the period from the start of the operation of DC / DC converter 40 to the elapse of a predetermined time (NO in S108), the stop suppression flag is turned on and charging device 20 and DC / DC converter 40 The operation is continued (S114).

  The auxiliary battery 50 is charged by the operation of the DC / DC converter 40. As a result, the SOC of the auxiliary battery 50 is restored, so that the electric power used for charging the auxiliary battery 50 among the input electric power from the external power supply 160 decreases with the passage of time. Therefore, the charging power of the main battery 30 increases as time passes from time t (0). Then, the charging power of the main battery 30 becomes equal to or higher than the threshold value PB when a certain time t has elapsed from the time t (0). Then, at time t (1), when the predetermined time has elapsed (YES in S108), the charging power is higher than threshold value PB (that is, the magnitude of current IB is the second threshold value). (Because it is larger than the value) (NO in S110), the operations of charging device 20 and DC / DC converter 40 are continued (S114).

  When the predetermined time has elapsed (YES in S108), the charging power is equal to or lower than threshold value PB (that is, the magnitude of current IB is equal to or lower than the second threshold value) ( If YES in S110), the operations of charging device 20 and DC / DC converter 40 are stopped (S112).

  As described above, according to the electric vehicle of the present embodiment, the charging device 20 and the DC / DC converter are operated from the start of the operation of the DC / DC converter 40 to the elapse of a predetermined time. By continuing the operation of 40, the charging of the main battery 30 can be continued. Therefore, when the charging of the main battery 30 is started in response to the user's request (for example, the charging plug 150 is attached to the inlet 70 by the user), the charging in response to the user's request can be continued. Therefore, it is possible to suppress deterioration of convenience. On the other hand, when the magnitude of the current IB of the main battery 30 is smaller than the second threshold value after the elapse of the predetermined time, the charging of the main battery 30 is stopped. Therefore, it is possible to prevent the state where it is difficult to clearly determine whether the battery is being charged or discharged from continuing. Therefore, it is possible to prevent the main battery 30 from becoming overcharged or overdischarged. Therefore, even if the electric power supplied from the outside is small, it is possible to provide the electric vehicle that continues charging the main battery and suppresses the deterioration of convenience.

Hereinafter, modified examples will be described.
In the above-described embodiment, the vehicle 1 has been described as being equipped with one DC / DC converter 40, but the vehicle 1 may be equipped with a plurality of DC / DC converters. FIG. 5 is a block diagram schematically showing an overall configuration of the electric vehicle 1 according to the modification. FIG. 5 differs from FIG. 1 in that a sub DC / DC converter 90 is included instead of the DC / DC converter 40, and a main DC / DC converter 80 is further included. Since the other configurations are similar, detailed description thereof will not be repeated.

  The main DC / DC converter 80 is connected in parallel with the sub DC / DC converter 90 between the main battery 30 and the auxiliary battery 50. Main DC / DC converter 80 supplies electric power to auxiliary battery 50 for charging when vehicle 1 is traveling, and also supplies electric power to high-voltage and low-voltage auxiliary loads mounted on vehicle 1. Therefore, the main DC / DC converter 80 consumes not only the charging power of the auxiliary battery 50 but also the overall power consumption of the auxiliary loads of the high-voltage system and the low-voltage system mounted on the ECU 100 and the vehicle 1 when the vehicle 1 is traveling. It has an output capacity set so that it can output.

  The sub DC / DC converter 90 supplies electric power to the auxiliary battery 50 for charging during external charging, and also supplies electric power to a low voltage system auxiliary load that operates during external charging. The sub DC / DC converter 90 has an output capacity set so as to output the power consumption of the low-voltage auxiliary load that operates during external charging, in addition to the charging power of the auxiliary battery 50 during external charging. Have. Therefore, the main DC / DC converter 80 has a higher output capacity than the sub DC / DC converter 90.

  Since the main DC / DC converter 80 has a higher output capacity, in the case where the SOC of the auxiliary battery 50 decreases during external charging, the auxiliary battery 50 is used to quickly increase the SOC of the auxiliary battery 50. It is conceivable to switch the DC / DC converter used for charging 50 from the sub DC / DC converter 90 to the main DC / DC converter 80.

  In such a case, by switching to the main DC / DC converter 80, of the input power from the external power supply 160, the power allocated to charging the auxiliary battery 50 becomes large, and therefore, as in the above-described embodiment, The charging power of the main battery 30 may be small.

  Therefore, in this modification, ECU 100 determines that the magnitude of current IB of main battery 30 is greater than the second threshold value after a predetermined time has elapsed from the start of operation of main DC / DC converter 80. When it falls, the operations of the charging device 20 and the main DC / DC converter 80 are stopped.

  The operation of the ECU 100 in the present modification is different in that the charge relay 60 is turned on when the charge plug 150 is connected to the inlet 70, and the operation of the sub DC / DC converter 90 is started. Further, in the present modification, when the SOC of auxiliary battery 50 decreases as compared with the flowchart in FIG. 3, ECU 100 performs a process of turning off charging relay 60 instead of the process of turning on charging relay 60 in S104. Instead of the process of operating the DC / DC converter 40 in S106, a process of switching the DC / DC converter used for charging the auxiliary battery 50 from the sub DC / DC converter 90 to the main DC / DC converter 80 is executed. The point is different. Other operations are similar to those in the flowchart of FIG. 3, and therefore detailed description thereof will not be repeated.

  The operation of the ECU 100 in the present modification based on the structure and processing described above will be described with reference to FIG. FIG. 6 is a timing chart for explaining the operation of the ECU 100 in this modification. The timing chart shown in FIG. 6 is premised on, for example, the case where external charging is being performed and the SOC of auxiliary battery 50 has not dropped.

  LN1 'in FIG. 6 indicates a change in charging power of the main battery 30. LN2 'of FIG. 6 shows the change of the command voltage of the auxiliary battery 50. LN3 'in FIG. 4 indicates a change in the stop suppression flag. The lowermost graph in FIG. 6 shows the DC / DC converter used for charging. The horizontal axis of FIG. 6 indicates time.

  As shown by LN1 'in FIG. 6, it is assumed that the charging power of main battery 30 is higher than threshold value PB, for example. Note that, as described above, it is assumed that the sub DC / DC converter 90 operates at the start of external charging and is used for charging the auxiliary battery 50. It is assumed that the charging power of the main battery 30 is periodically changed by the operation of the sub DC / DC converter 90.

  Further, as indicated by LN2 'in FIG. 6, it is assumed that the command voltage of auxiliary battery 50 is VA (1). It is assumed that the command voltage for auxiliary battery 50 also changes periodically due to the operation of sub DC / DC converter 90.

  Further, as shown by LN3 'in FIG. 6, it is assumed that the stop suppression flag is in the off state.

  During external charging, when the SOC of auxiliary battery 50 is higher than the first threshold value, the operation of sub DC / DC converter 90 is continued. On the other hand, at time t (2), when the SOC of auxiliary battery 50 falls below the first threshold value, charging relay 60 is turned off and DC used for charging auxiliary battery 50 is turned off. The / DC converter is switched from the sub DC / DC converter 90 to the main DC / DC converter 80.

  The operation of the main DC / DC converter 80 is started, and the command voltage of the auxiliary battery 50 rises to VA (0). Therefore, since the amount of the input power input from external power supply 160 that is allocated to charge auxiliary battery 50 increases, the charging power of main battery 30 decreases to PB (1) lower than threshold value PB. . From the start of the operation of the main DC / DC converter 80 to the elapse of a predetermined time, the stop suppression flag is turned on, and the operations of the charging device 20 and the main DC / DC converter 80 are continued. It

  The auxiliary battery 50 is charged by the operation of the main DC / DC converter. As a result, the SOC of the auxiliary battery 50 is restored, so that the electric power used for charging the auxiliary battery 50 among the input electric power from the external power supply 160 decreases with the passage of time. Therefore, the charging power of the main battery 30 increases as time passes from time t (2). Then, the charging power of the main battery 30 becomes equal to or higher than the threshold value PB when a certain time t has elapsed from the time t (2). Then, at time t (3), when the predetermined time has elapsed, the charging power is higher than the threshold value PB (that is, the magnitude of the current IB is larger than the second threshold value). The charging device 20 and the main DC / DC converter 80 continue to operate.

  When the charging power is equal to or lower than the threshold value PB (that is, the magnitude of the current IB is equal to or lower than the second threshold value) after a predetermined time has elapsed, the charging device 20 and the main DC The operation of the / DC converter 80 is stopped.

  Even in this case, even if the charging power of the main battery 30 is reduced due to the charging of the auxiliary battery 50, the charging is not stopped until a predetermined time has elapsed after the switching to the main DC / DC converter 80. Therefore, it is possible to suppress the deterioration of user convenience. Furthermore, when the charging power of the main battery 30 is small even after the elapse of a predetermined time, the operations of the charging device 20 and the main DC / DC converter 80 are stopped, so that the main battery 30 is charged. It is suppressed that the state in which it is difficult to clearly determine whether it is discharged or discharged is continued. Therefore, it is possible to prevent the main battery 30 from becoming overcharged or overdischarged.

  Further, in the above-described embodiment, current is supplied from the start of the operation of DC / DC converter 40 until a predetermined time elapses, on condition that the SOC of auxiliary battery 50 is equal to or lower than the first threshold value. Although it has been described that it is determined whether or not the magnitude of the current IB is reduced after a predetermined time elapses without determining whether or not the magnitude of IB is reduced. It is not limited to such conditions. For example, in addition to the case where the SOC of auxiliary battery 50 becomes equal to or lower than the first threshold value, the case where the SOC of main battery 30 is between a predetermined upper limit value and a lower limit value may be a condition. In this way, it is possible to prevent the main battery 30 from becoming overcharged or overdischarged.

  In the above-described embodiment, vehicle 1 has been described as an example of an electric vehicle that uses a motor as a drive source, but vehicle 1 may be, for example, a hybrid vehicle that includes an engine that has at least a function as a generator. Good.

The above-described modified examples may be implemented by appropriately combining all or part of them.
The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

  1 Electric Vehicle, 10 Electric Load, 12 MG, 14 PCU, 20 Charging Device, 30 Main Battery, 40 DC / DC Converter, 50 Auxiliary Battery, 60 Charging Relay, 70 Inlet, 80 Main DC / DC Converter, 90 Sub DC / DC converter, 100 ECU, 102 current sensor, 150 charging plug, 152 charging cable, 160 external power supply.

Claims (1)

A rotating electric machine that is a drive source for running the vehicle,
A first power storage device for supplying electric power to the rotating electric machine;
A second power storage device for supplying electric power to an auxiliary device mounted on the vehicle;
A first power conversion device for converting AC power from an external power supply provided outside the vehicle into first DC power capable of charging the first power storage device and outputting the first DC power to the first power storage device;
A second power converter for converting the first DC power converted in the first power converter into second DC power capable of charging the second power storage device and outputting the second DC power to the second power storage device; ,
A control device that controls the operation of the first power conversion device and the operation of the second power conversion device;
The control device operates the first power conversion device when the AC power is supplied to the vehicle from the external power supply, and when the remaining capacity of the second power storage device is lower than a first threshold value. , Further activating the second power converter,
When the magnitude of the current of the first power storage device is lower than the second threshold value, the first power storage device is operated in the first power storage device until the predetermined time elapses after the operation of the second power conversion device is started. The first power conversion device and the second power conversion device are continuously operated, and after the predetermined time has elapsed from the start of the operation of the second power conversion device, the first power conversion device and the first power conversion device 2 An electric vehicle that stops the operation of the power converter.

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