Control method and control device for vehicle charging system

Abstract

A control method for a vehicle charging system calculates a second current by subtracting the rated current of an outlet from a first current that can be supplied from an external power supply to an electric vehicle, charges a battery with the second current, determines whether a load is connected to the outlet while the battery is being charged with the second current, simultaneously supplies power from the external power supply to the load and the battery when the load is connected to the outlet, determines whether the maximum value of an output current being supplied from the external power supply to the load and falling within a predetermined current range successively occurs a predetermined number of instances or more within a predetermined time, and, when the maximum value of the output current falling within the predetermined current range successively occurs the predetermined number of instances or more within the predetermined time, calculates a third current smaller than the rated current by adding a margin value to the maximum value of the output current, and charges the battery with a fourth current obtained by subtracting the third current from the first current.

Description

Control Method and Control Device for Vehicle Charging System

[0001] The present disclosure relates to a control method and a control device for a vehicle charging system.

[0002] In electric vehicles such as electric cars and hybrid cars, a system that converts the DC power of a high-voltage driving battery into AC power and supplies power to electrical equipment outside the vehicle has been put into practical use. There is known a charging and power supply device for an electric vehicle that can charge the battery of the electric vehicle and supply power to electrical equipment outside the vehicle using a charging cable connected to the charging port of the electric vehicle.

[0003] Japanese Patent No. 6093981

[0004] There is a problem that it is impossible to simultaneously charge the battery of an electric vehicle and supply power to electrical equipment outside the vehicle.

[0005] An object of the present disclosure is to provide a control method and a control device for a vehicle charging system that can efficiently charge a battery in a vehicle charging system capable of simultaneously charging the battery of an electric vehicle and supplying power to a load connected to a power outlet in the vehicle interior.

[0006] A control method for a vehicle charging system according to an aspect of the present disclosure calculates a second current obtained by subtracting the rated current of a power outlet from a first current that can be supplied from an external power source to an electric vehicle, charges the battery with the second current, and determines whether a load is connected to the power outlet when charging the battery with the second current. When a load is connected to the power outlet, power is simultaneously supplied from the external power source to the load and the battery, and it is determined whether a maximum value of an output current supplied from the external power source to the load, which is within a predetermined current range, occurs continuously a predetermined number of times or more within a predetermined time. When the maximum value of the output current within the predetermined current range occurs continuously a predetermined number of times or more within the predetermined time, a third current smaller than the rated current is calculated by adding a margin value to the maximum value of the output current, and the battery is charged with a fourth current obtained by subtracting the third current from the first current.

[0007] Figure 1A is a block diagram showing the overall configuration of the vehicle charging system 1 according to the first embodiment. Figure 1B is a block diagram showing the detailed configuration of the ECU 17 in Figure 1A. Figure 2A is a flowchart showing an example of a control method for the vehicle charging system 1. Figure 2B is a flowchart showing another example of a control method for the vehicle charging system 1. Figure 3 shows the output current C supplied to the load connected to the outlet 13. ｏｕｔ , operating status of timer 171, outlet distribution amount D ｏｕｔ , the charging current C of the HV battery 10 ｂａｔ This graph shows an example of the time variation of [a certain variable]. Figure 4A shows the output current C when charging a smartphone battery, which is an example of a load. ｏｕｔ This is a graph showing an example of the waveform. Figure 4B is an enlarged graph of Figure 4A from time t21 to t22. Figure 5 is a flowchart showing the control method of the vehicle charging system 1 according to the second embodiment. Figure 6A shows the output current C supplied to the load connected to the outlet 13. ｏｕｔ , operating status of timer 171, outlet distribution amount D ｏｕｔ , the charging current C of the HV battery 10 ｂａｔ This graph shows another example of the time variation of [variable]. Figure 6B is an enlarged graph of a portion (22, 23) of Figure 6A. Figure 7 shows the output current C over a long period of time. ｏｕｔ This graph illustrates an example of a control method for the vehicle charging system 1 when the system is stable.

[0008] The embodiments will be described with reference to the drawings. In the drawings, the same parts are denoted by the same reference numerals and their descriptions are omitted.

[0009] (First Embodiment) [Vehicle Charging System] Referring to Figure 1A, the overall configuration of the vehicle charging system 1 according to the first embodiment will be described. The vehicle charging system 1 is configured to supply power to a load connected to an outlet 13a or outlet 13b inside the vehicle cabin of the electric vehicle 2, using a BOBC (Bidirectional Onboard Charger) 11 that can charge and discharge in both directions between an HV (High Voltage) battery 10, which is an example of a battery mounted on the electric vehicle 2, and an external power source 3.

[0010] The electric vehicle 2 refers to an automobile that uses electricity for propulsion, such as an electric vehicle (EV), hybrid vehicle (HV), plug-in hybrid vehicle (PHEV), or fuel cell vehicle (FCV). The HV battery 10 is a high-voltage battery used to drive the electric vehicle 2 and has an output voltage of approximately 100V to 800V.

[0011] The external power supply 3 is electricity (commercial power) commonly used in homes, factories, offices, etc. For example, in Japan, the external power supply 3 is AC 100V or AC 200V. One connector of the charging cable 4 (EVSE: Electric Vehicle Supply Equipment) can be electrically connected to the outlet of the external power supply 3, and the other connector of the charging cable 4 can be electrically connected to the standard charging port 16 of the electric vehicle 2. The electric vehicle 2 can be charged from the external power supply 3 using the charging cable 4. The rated current value of the charging cable 4 is, for example, 20 [A]. Therefore, the maximum current (first current) that can be supplied from the external power supply 3 to the electric vehicle 2 is 20 A. However, the rated current value of the charging cable 4 is just an example and is not limited to 20 [A]; other values ​​may also be used.

[0012] The standard charging port 16 is electrically connected to the HV battery 10 via the PDU 12 and BOBC 12. The standard charging port 16 is also electrically connected to the outlets 13a and 13b via the PDU 12. Using the external power supply 3, the HV battery 10 can be charged and power can be supplied to the loads connected to the outlets 13a and 13b simultaneously.

[0013] The BOBC 12 enables charging and discharging of the HV battery 10 by converting voltage bidirectionally between alternating current (AC) and direct current (DC). This allows power to be supplied from the HV battery 10 to an external load connected to the outlets 13a, 13b in the vehicle interior or the standard charging port 16. Furthermore, the BOBC 12 can adjust the charging and discharging currents of the HV battery 10 under the control of the ECU 17.

[0014] The PDU 12 (Power Distribution Unit) distributes power between the HV battery 10, outlets 13a and 13b, and the standard charging port 16. For example, the PDU 12 distributes the power supplied from the external power source 3 to the standard charging port 16 to the HV battery 10 and outlets 13a and 13b. This allows for simultaneous charging of the HV battery 10 of the electric vehicle 2 and power supply to loads connected to outlets inside the vehicle. The maximum current (first current) that can be supplied from the external power source 3 to the standard charging port 16 is, for example, 20 [A]. Therefore, the sum of the charging current of the HV battery 10 and the output current supplied to loads connected to outlets 13a and 13b cannot exceed the rated current value of the charging cable 4.

[0015] Ammeters 14a, 14b, and 15 are provided on the wires connected to outlets 13a and 13b, and the HV battery 10, respectively. Ammeters 14a and 14b measure the current supplied to the loads connected to outlets 13a and 13b. Ammeter 15 measures the charging current and discharging current of the HV battery 10. Signals indicating the current values ​​measured by ammeters 14a, 14b, and 15 are transmitted to an ECU 17, which is an example of a control unit for the vehicle charging system 1.

[0016] The outlets 13a and 13b (plug, plug socket, outlet) are connection points for supplying power to various types of electrical appliances (loads). For example, in Japan, outlets 13a and 13b include 2-prong outlets (JIS C 8303) with a rating of 12A / 125V. The number of outlets 13a and 13b is not limited to 2; it may be 1 or 3 or more. In addition, an ammeter may be provided for each outlet, but a single ammeter may be used to measure the total value of the current supplied from all outlets 13a and 13b. The total value of the current supplied from all outlets 13a and 13b is input to the ECU 17. Hereafter, when outlets 13a and 13b are not distinguished, they will be referred to as "outlet 13". The total value of the output current supplied from all outlets 13a and 13b will be referred to as "output current supplied to the load connected to outlet 13" or simply "output current".

[0017] The ECU 17 (Electronic Control Unit) is a microcomputer that electronically controls the vehicle charging system 1. The ECU 17 includes a microcontroller (MCU), memory including RAM (Random-access memory) and ROM (Read Only Memory), and an input / output interface. Analog signals indicating current values ​​measured by ammeters 14a, 14b, and 15 are converted into digital signals by the input / output interface.

[0018] A computer program (control program) for making the ECU 17 function as a control device for the vehicle charging system 1 is installed on and executed in the ECU 17. As a result, the ECU 17 functions as one of the multiple information processing units (171-174) provided by the control device.

[0019] Here, we show an example of implementing the control device for the vehicle charging system 1 using software. However, it is also possible to configure the control device for the vehicle charging system 1 by preparing dedicated hardware, such as application-specific integrated circuits (ASICs), to execute each information processing step. The multiple information processing units (171 to 174) included in the control device for the vehicle charging system 1 may also be configured using individual hardware.

[0020] The ECU 17 includes, as described above, a timer 171, an output current monitoring unit 172, a counter 173, and a charging current control unit 174 as multiple information processing units.

[0021] The timer 171 counts the elapsed time since startup, under the control of the output current monitoring unit 172. The counter 173 counts the number of times the maximum value of the output current occurs, under the control of the output current monitoring unit 172.

[0022] The output current monitoring unit 172 monitors the output current supplied to the load connected to the outlet 13 using the current values ​​measured by the ammeters 14a and 14b. Based on the output current, the output current monitoring unit 172 determines whether the operation of the load connected to the outlet 13 has stabilized. When the operation of the load stabilizes, the output current oscillates at a predetermined period, and the maximum value of the output current falls within a certain range. Based on the state of the output current, the output current monitoring unit 172 determines whether the operation of the load has stabilized.

[0023] The output current monitoring unit 172 counts the number of times the output current reaches its maximum value using a counter 173. The output current monitoring unit 172 counts the number of times the output current reaches its maximum value within a predetermined current range occur consecutively. The output current monitoring unit 172 determines whether the output current reaches its maximum value within a predetermined current range occur consecutively a predetermined number of times or more within a predetermined time. The output current monitoring unit 172 counts the predetermined time using a timer 171.

[0024] The charging current control unit 174 controls the charging current of the HV battery 10 using the current value measured by the ammeter 15. As mentioned above, the sum of the charging current and output current of the HV battery 10 cannot exceed the first current (20 [A]). Furthermore, it is difficult to predict the output current before the operation of the load stabilizes. Therefore, the charging current control unit 174 distributes the rated current (15 [A]) of the first current that can be supplied from the external power source 3 to the electric vehicle 2 to the outlet 13. The charging current control unit 174 charges the HV battery 10 with a second current (5 [A]), which is the first current minus the rated current of the outlet 13 (15 [A]). This prevents the sum of the output current and charging current from exceeding the first current.

[0025] When the operation of the load connected to the outlet 13 stabilizes, the charging current control unit 174 distributes a third current smaller than the rated current (15 [A]) to the outlet 13, and charges the HV battery 10 with a fourth current obtained by subtracting the third current from the first current. Since the fourth current is larger than the second current, the HV battery 10 can be charged efficiently in a short time.

[0026] [Control Method of Vehicle Charging System] An example of a control method for the vehicle charging system 1 using the control device (ECU17) of the vehicle charging system 1 will be described. Referring to FIGS. 2A to 3, a control method for the vehicle charging system 1 when simultaneously charging the HV battery 10 and supplying power to the loads connected to the outlets 13a and 13b using the off-vehicle power source 3 will be described. Hereinafter, the amount of current distributed to the outlet 13 may be referred to as "outlet distribution amount D" ｏｕｔ ".

[0027] The flowchart of FIG. 2A and the graph of FIG. 3 start with the charging current control unit 174 starting the charging of the HV battery using the off-vehicle power source 3. In step S01, the charging current control unit 174 sets the rated current (15 [A]), which is the largest current value that can flow through the outlet 13, to the outlet distribution amount D ｏｕｔ . This is because there are many types of loads, and the output current of the load varies depending on the type of load, and it is difficult to estimate in advance the output current of the load connected to the outlet 13. Then, the charging current control unit 174 sets the second current obtained by subtracting the rated current of the outlet 13 from the first current that can be supplied from the off-vehicle power source 3 to the electric vehicle 2 as the charging current C ｂａｔ of the HV battery 10.

[0028] Proceeding to step S02, the ECU 17 determines whether the charging of the HV battery 10 is normal charging via the normal charging port 16. If the determination is affirmative, the process proceeds to step S03. As shown in FIG. 3, when a load is connected to the outlet 13 during the charging of the HV battery 10, the ECU 17 simultaneously supplies power from the off-vehicle power source 3 to both the load and the HV battery 10. The output current C ｏｕｔ supplied to the load increases and exceeds the reference value (α) at time t1. In step S03, the charging current control unit 174 detects that the output current C ｏｕｔ has exceeded the reference value (α). Thereby, the charging current control unit 174 determines that a load is connected to the outlet 13. The reference value (α) is, for example, a value larger than the leakage current flowing through the outlet 13 in a state where no load is connected to the outlet 13 and smaller than the current flowing during the normal operation of the load.

[0029] The process proceeds to step S04, where the output current monitoring unit 172 activates the timer 171 and proceeds to step S05, where it counts the elapsed time from time t1. Simultaneously, the output current monitoring unit 172 uses the counter 173 to calculate the output current C ｏｕｔ Count the number of times the maximum value of occurs.

[0030] If a predetermined time PT[s] has elapsed since the timer 171 was started (YES in step S05), the process proceeds to step S06, where the output current monitoring unit 172 checks if the output current C falls within a predetermined current range (B1±H) within the predetermined time PT[s]. ｏｕｔ It is determined whether the maximum value of has occurred consecutively for a predetermined number of times (D times: for example, 5 times) or more. As shown in Figure 3, the predetermined current range (B1±H) is determined based on the maximum value B1 of the output current measured by ammeters 14a and 14b. The predetermined current range (B1±H) is the range between the maximum value (B1) minus the margin H and the maximum value B1 plus the margin H. The predetermined number of times (D times), predetermined time PT[s], and margin H are the output current C of a specific electrical product assumed to be a load connected to an outlet in the vehicle interior. ｏｕｔ It is predetermined based on the waveform.

[0031] As shown in Figure 3, the output current C falls within a predetermined current range (B1 ± H). ｏｕｔ The maximum values ​​N1 to N5 occur a predetermined number of times (for example, 5 times) or more within a predetermined time PT [s] from time t1 to time t2. Therefore, the output current monitoring unit 172 determines that the operation of the load connected to the outlet 13 has stabilized (YES in step S06) and proceeds to step S08.

[0032] When the load operation stabilizes, the output current C ｏｕｔ The power supply also stabilizes. Therefore, in step S08, the charging current control unit 174 calculates a third current (B1 + M) which is smaller than the rated current of the outlet 13, by adding a margin value M to the maximum value B of the output current, and distributes the third current (B1 + M) to the outlet 13. The charging current control unit 174 then sets the fourth current, obtained by subtracting the third current (B1 + M) from the first current, to the charging current C of the HV battery 10. ｂａｔTherefore, since the fourth current is larger than the second current in step S01, the HV battery 10 can be charged efficiently in a short time.

[0033] In the example shown in Figure 3, at time t2, the charging current control unit 174 controls the outlet distribution amount D. ｏｕｔ The current is changed from the rated current to the third current (B1 + M), and at the same time, the charging current C of the HV battery 10 is changed. ｂａｔ This changes the current from the second current to the fourth current. As a result, the outlet distribution amount D ｏｕｔ and charging current C ｂａｔ While maintaining the sum of these to the maximum current (first current) that can be supplied from the external power source 3 to the normal charging port 16, the charging current C ｂａｔ This can increase the charging capacity. Therefore, the HV battery 10 can be charged efficiently in a short time while protecting the charging cable 4.

[0034] On the other hand, if the answer in step S06 is NO, it can be determined that the load operation is not stable. Therefore, after resetting the timer 171 in step S07, the process returns to step S01, and the charging current control unit 174 distributes the rated current to the outlet 13 and charges the HV battery 10 with the second current.

[0035] The flowchart in Figure 2B shows the output current C after step S08 in Figure 2A has been performed. ｏｕｔ The system starts when the output current C exceeds the third current (B1 + M). In the example in Figure 3, at time t3, the output current C ｏｕｔ The third current (B1 + M) is exceeding the limit.

[0036] Proceeding to step S11, the charging current control unit 174 controls the outlet distribution amount D ｏｕｔ The third current (B1 + M) is changed to the rated current of outlet 13. The charging current control unit 174 controls the charging current C of the HV battery 10. ｂａｔ The output current C is changed from the fourth current to the second current. ｏｕｔ In response to the increase, sufficient outlet distribution amount D ｏｕｔ This can be secured.

[0037] Subsequently, in steps S12 to S18 of Figure 2B, the same processing as in steps S02 to S08 of Figure 2A is performed. As a result, the output current monitoring unit 172 determines the output current C ｏｕｔ It determines whether the system is stable or not. Then, the output current C ｏｕｔ When the current stabilizes, the charging current control unit 174 controls the outlet distribution amount D ｏｕｔ The current is changed from the rated current to the third current (B2 + M), and at the same time, the charging current C of the HV battery 10 is changed. ｂａｔ The current is changed from the second current to the fourth current. The graph in Figure 3 shows the output current C. ｏｕｔ After the third current (B1 + M) is exceeded, the output current C ｏｕｔ Because it is stable, the output current C at this time ｏｕｔ This example shows that the maximum value B2 is greater than the maximum value B1 before the third current (B1 + M) is exceeded.

[0038] In the example shown in Figure 3, the output current C is at time t3. ｏｕｔ Since it has already exceeded the reference value (α), the timer is reset and then the timer 171 is started again (step S14). Within a predetermined time PT [s] from time t3 to time t5, the output current C falls within a predetermined current range (B2±H). ｏｕｔ The maximum values ​​(N1 to N4) have not occurred consecutively for a predetermined number of times (D times: for example, 5 times). Therefore, in step S16 of Figure 2B, it is determined to be NO.

[0039] As explained above, if the judgment made in steps S06 and S16 is positive, the output current C ｏｕｔ The maximum value falls within the predetermined current range (B1±H, B2±H), and it can be determined that the load operation is stable. In this case, the outlet distribution amount D ｏｕｔ Reduce the current to the third current (B1+M, B2+M), and the outlet distribution amount D ｏｕｔ The decrease is due to the charging current C of the HV battery 10. ｂａｔ This is used to charge the HV battery 10 efficiently in a short amount of time.

[0040] And the output current C ｏｕｔ If the current exceeds the predetermined current range (B1±H, B2±H), the outlet distribution amount Dｏｕｔ Increase the current up to the rated current. This will provide sufficient outlet distribution D ｏｕｔ This ensures that the current flowing through the charging cable 4 does not exceed the rated current (20 [A]).

[0041] Figure 4A shows the output current C when charging a smartphone battery, which is an example of a load. ｏｕｔ This graph shows an example of the waveform. Figure 4B is an enlarged view of Figure 4A from time t21 to t22. Note that the load is not limited to smartphones, but includes all electrical products that can operate or be charged with power supplied from the outlet 13.

[0042] At time t21, the smartphone is connected to outlet 13. Before time t21, it is not connected. While not connected, a small dark current flows through outlet 13. Immediately after connection, a surge current 21 or inrush current flows instantaneously (Figure 4B). After a certain period of waiting, the smartphone starts charging at time t23. From time t23 onward, the output current C ｏｕｔ The maximum value of the current falls within a predetermined current range (B1±H), and the operation (charging operation) of the load (smartphone) is stable.

[0043] The output current monitoring unit 172 starts the timer 171 at time t21. Then, within a predetermined time PT[s] from time t21 to time t24, the output current C falls within a predetermined current range (B1±H). ｏｕｔ The maximum value of occurs for a predetermined number of consecutive times (for example, 5 times) or more, and the charging current control unit 174 determines that the outlet distribution amount D after time t24 is ｏｕｔ Reduce the current to the third current (B2 + M), and the outlet distribution amount D ｏｕｔ The decrease is due to the charging current C of the HV battery 10. ｂａｔ It can be added to. The region indicated by reference numeral 20 in Figure 4A is the output current C that falls within a predetermined current range (B1 ± H). ｏｕｔ This indicates a region where the maximum value of occurs consecutively for a predetermined number of times (e.g., 5 times) or more.

[0044] (Second Embodiment) Referring to Figures 5, 6A and 6B, the output current C ｏｕｔA second embodiment of the control method for the vehicle charging system 1 when the third current (B1 + M) is exceeded will be described. In the second embodiment, the configuration of the vehicle charging system 1 (Figures 1A and 1B) and the flowchart in Figure 2A are the same as in the first embodiment. In the second embodiment, the output current C per unit time Δt is ｏｕｔ The amount of outlet distribution D depends on the increase in △i. ｏｕｔ and the charging current C of the HV battery 10 ｂａｔ Change it at a finite rate of change.

[0045] The flowchart in Figure 5 shows the output current C after step S08 in Figure 2A has been executed. ｏｕｔ It starts when the output current C exceeds the third current (B1 + M). At time t3 in Figure 6A, the output current C ｏｕｔ The third current (B1 + M) exceeds the current and is increasing more gradually compared to Figure 3. As shown in Figure 6B, the outlet distribution amount D ｏｕｔ Output current C ｏｕｔ Let f [A] be the value obtained by subtracting C, and let C be the output current per unit time Δt. ｏｕｔ Let the increase be △i. At this time, in step S21 of Figure 5, we determine whether equation (1) is satisfied. f[A] - △i > △i ... (1)

[0046] (1) If equation is satisfied (YES in step S21), proceed to step S22 and determine the outlet distribution amount D ｏｕｔ The value obtained by adding the increase amount △i to this is the new outlet distribution amount D ｏｕｔ Set to this value. Then return to step S21. Repeat steps S21 and S22 as long as equation (1) is satisfied. Note that the unit time Δt is the repetition period of steps S21 and S22, and may be, for example, the processing period of the ECU 17 (for example, 1 ms).

[0047] As shown in Figure 6B, equation (1) is satisfied at time t12. Therefore, at time t13, which is the next calculation cycle, the outlet distribution amount D ｏｕｔ The value obtained by adding the increase amount △i to this is the new outlet distribution amount D ｏｕｔ Set it to this. In this way, outlet distribution amount D ｏｕｔ and output current C ｏｕｔThe difference f[A] is the output current C ｏｕｔ As long as the increase is less than △i, the outlet distribution amount D ｏｕｔ This increases the difference f [A]. As a result, the output current C ｏｕｔ With a finite rate of change corresponding to a gradual increase in the outlet distribution amount D ｏｕｔ By increasing the charging current C of the HV battery 10 at a similar finite rate of change, ｂａｔ It can reduce the output current C. ｏｕｔ Even if the third current (B1 + M) is exceeded, the charging current C of the HV battery 10 ｂａｔ This suppresses a rapid decrease in energy and maintains efficient charging of the HV battery 10.

[0048] (Third Embodiment) Referring to Figure 7, the output current C over a long period of time ｏｕｔ A third embodiment of the control method for the vehicle charging system 1 when the system is stable will be described. In the third embodiment, the configuration of the vehicle charging system 1 (Figures 1A and 1B) is the same as in the first embodiment. However, the timer 171 in Figure 1B differs from the first embodiment in that it can count a time longer than a predetermined time PT[s] as the elapsed time since startup.

[0049] As shown in Figure 7, the output current C falls within a predetermined current range (B1 ± H). ｏｕｔ The maximum values ​​N1 to N5 occur a predetermined number of times (for example, 5 times) or more within a predetermined time PT0 [s] from time t1 to time t2. Therefore, the output current monitoring unit 172 determines that the operation of the load connected to the outlet 13 has stabilized. Note that the predetermined time PT0 [s] corresponds to the predetermined time PT [s] in the first embodiment.

[0050] The charging current control unit 174 distributes a third current (B1 + M1), which is smaller than the rated current of the outlet 13, to the outlet 13 by adding a first margin value M1 to the maximum output current B. Then, it charges the HV battery 10 with a fourth current, which is obtained by subtracting the third current (B1 + M1) from the first current.

[0051] Subsequently, the timer 171 continues to count the elapsed time. During the predetermined time (PT1-PT0 [S]) from time t2 to time t6, the output current C falls within a predetermined current range (B1±H). ｏｕｔ The maximum values ​​N6 to N10 have occurred a predetermined number of times (for example, 5 times) or more. Therefore, the charging current control unit 174 distributes a third current (B1 + M2), which is the maximum value B1 of the output current plus a second margin value M2, to the outlet 13. Then, it charges the HV battery 10 with a fourth current, which is the first current minus the third current (B1 + M2).

[0052] Here, by making the second margin value (M2) smaller than the first margin value (M1), the fourth current can be increased. Similarly, if the maximum value B of the output current is stable during the predetermined time (PT2-PT1[S]) from time t6 to time t7, the third and fourth currents are calculated using a third margin value M3 that is smaller than the second margin value (M2). In this way, the output current C falls within the predetermined current range (B1±H). ｏｕｔ The longer the time during which the maximum value of occurs continuously, or the output current C ｏｕｔ The more times the maximum value of occurs consecutively, the larger the fourth current used to charge the HV battery 10 can be. Therefore, the HV battery 10 can be charged efficiently in a short amount of time.

[0053] As described above, embodiments have been presented, but the statements and drawings that constitute part of this disclosure should not be understood as limiting the invention. Various alternative embodiments, examples, and operational techniques will become apparent to those skilled in the art from this disclosure.

[0054] In the flowcharts of Figures 2B and 5, the output current C ｏｕｔ The control method when the third current (B1 + M) is exceeded was explained. In contrast, after charging the HV battery 10 with the fourth current in step S08 or step S18, the output current C ｏｕｔ When the maximum value of becomes smaller than a predetermined current range (B1±H), the charging current C of the HV battery 10 ｂａｔ The fourth current may be maintained as is. Alternatively, the output current C ｏｕｔ The decrease is added to the fourth current, resulting in the charging current C.ｂａｔ may be increased. Output current C ｏｕｔ After the maximum value of the output current C becomes smaller than a predetermined current range (B1 ± H), when the output current C ｏｕｔ becomes stable, the third current and the fourth current may be set based on the maximum value of the output current C in the stable state. ｏｕｔ

[0055] 1 Vehicle charging system, 2 Electric vehicle, 3 External power source, 4 Charging cable, 10 HV battery (battery), 13a, 13b Socket, 14a, 14b, 15 Ammeter, 16 Normal charging port, 21 Surge current, 17 ECU (control device), 171 Timer, 172 Output current monitoring unit, 173 Counter, 174 Charging current control unit, B Maximum value, C [[ID=L11]] ｂａｔ Charging current, C ｏｕｔ Output current, D ｏｕｔ Socket distribution amount, M Margin value, M1 to M3 Margin values, N1 to Z10 Maximum values, △i Increase amount, △t Unit time

Claims

1. A control method for a vehicle charging system configured to supply power to a load connected to an outlet inside the vehicle of an electric vehicle, using a bidirectional onboard charger capable of charging and discharging bidirectionally between a battery mounted on the electric vehicle and an external power source, comprising: calculating a second current by subtracting the rated current of the outlet from a first current that can be supplied from the external power source to the electric vehicle, charging the battery with the second current; determining whether the load is connected to the outlet while the battery is being charged with the second current; if the load is connected to the outlet, simultaneously supplying the power from the external power source to the load and the battery; and determining whether the maximum value of the output current supplied from the external power source to the load, which falls within a predetermined current range, occurs consecutively a predetermined number of times or more within a predetermined time. A control method for a vehicle charging system, wherein if the maximum value of the output current that falls within the predetermined current range occurs consecutively a predetermined number of times or more within a predetermined time, a third current smaller than the rated current is calculated by adding a margin value to the maximum value of the output current, and the battery is charged with a fourth current obtained by subtracting the third current from the first current.

2. The control method for a vehicle charging system according to claim 1, wherein the predetermined current range is determined based on the maximum value of the output current.

3. A control method for a vehicle charging system according to claim 1 or 2, wherein if the output current exceeds the third current, the battery is charged with the second current.

4. A control method for a vehicle charging system according to claim 1 or 2, wherein if the output current increases beyond the third current, the fourth current is reduced in proportion to the amount of increase in the output current per unit time.

5. A control method for a vehicle charging system according to any one of claims 1 to 4, wherein the fourth current for charging the battery is increased as the duration of consecutive occurrences of the maximum value of the output current that falls within the predetermined current range increases, or as the number of consecutive occurrences of the maximum value increases.

6. A control device for a vehicle charging system configured to supply power to a load connected to an outlet inside the vehicle using a bidirectional onboard charger capable of charging and discharging bidirectionally between a battery mounted on the electric vehicle and an external power source, wherein the control device calculates a second current by subtracting the rated current of the outlet from a first current that can be supplied from the external power source to the electric vehicle, charges the battery with the second current, determines whether the load is connected to the outlet while the battery is being charged with the second current, if the load is connected to the outlet, simultaneously supplies the power from the external power source to the load and the battery, and determines whether the maximum value of the output current supplied from the external power source to the load, which falls within a predetermined current range, occurs consecutively a predetermined number of times or more within a predetermined time. A control device for a vehicle charging system, configured such that, if the maximum value of the output current that falls within the predetermined current range occurs consecutively a predetermined number of times or more within a predetermined time, a third current smaller than the rated current is calculated by adding a margin value to the maximum value of the output current, and the battery is charged with a fourth current obtained by subtracting the third current from the first current.

Images