Charging device control device, charging device control method, and charging system

Abstract

The invention relates to a control device of charging equipment, a control method of charging equipment and a charging system. The electric vehicle power supply equipment uses the voltage (VB) of the storage battery before the start of charging to obtain the maximum value of the output power and the maximum value of the output current. The output power maximum value and the output current maximum value are set to be smaller when the voltage is low than when the voltage is high. The output current value is calculated on the basis of the output power maximum value, and is set to be smaller when the voltage is low than when the voltage is high.

Description

Technical Field

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

[0002] Japanese Patent Application Laid-Open No. 2018-38198 discloses a vehicle having a power storage device that can be charged using an external power supply. In Japanese Patent Application Laid-Open No. 2018-38198, the power storage device is charged according to the smaller of a charging current command value set according to the output current of the charging pile and a charging power command value set according to the required power of the vehicle. Summary of the invention

[0003] In Japanese Patent Laid-Open No. 2018-38198, information about the output current of the charging pile is provided from the charging pile to the vehicle. When components designed for vehicles are effectively utilized (converted) into components used for the charging pile, etc., there may be a situation where the output voltage of the charging pile does not meet the lower limit voltage of the specification value (design value) of the charging pile. When the output voltage of the charging pile becomes a voltage lower than the lower limit output voltage, even a low voltage is limited to an allowable output, so that sometimes the charging current output from the charging pile becomes smaller than the output current. In this case, the charging current output from the charging pile deviates from the charging current command value, and charging may be stopped due to abnormal charging processing.

[0004] An object of the present disclosure is to enable stable charging even when the output voltage of a charging device is lower than a lower limit voltage.

[0005] A control device for charging equipment of the present disclosure is a control device for charging equipment that charges a battery mounted on a vehicle.

[0006] The control device is configured to transmit a value of an outputtable current that can be outputted from the charging facility to the vehicle.

[0007] The outputtable current value is set so as to be smaller when the voltage of the storage battery, that is, the battery voltage is low than when the battery voltage is high.

[0008] According to this structure, the control device of the charging device sends the output current value that can be output from the charging device to the vehicle. In addition, the output current value is set in a manner that is smaller when the battery voltage is low than when the battery voltage is high. For example, the lower the battery voltage, the smaller the output current value. Therefore, when the voltage of the battery being charged (battery voltage) is low, the output current value becomes smaller, so even if the output voltage of the charging device is lower than the lower limit voltage, the range that can be charged is expanded, and stable charging can be achieved.

[0009] Preferably, the battery voltage may be the voltage of the secondary battery before starting charging of the secondary battery.

[0010] The control device sets the outputtable current value before starting charging of the storage battery.

[0011] Generally, the battery voltage before charging starts is lower than the battery voltage after charging starts. Therefore, it is possible to suppress the output current value from becoming unnecessarily large, and charging can be performed stably. The battery voltage before charging starts can be detected by a voltage sensor provided in the charging device. In addition, when charging starts, information on the common lower limit voltage value of the battery can be sent from the vehicle before charging starts, and the common lower limit voltage value can be used as the battery voltage before charging starts.

[0012] Preferably, the control device can reset the outputtable current value based on the battery voltage during charging of the storage battery.

[0013] According to this configuration, the output current value is reset based on the battery voltage during charging. If the battery voltage rises during charging, the output current value increases, so the charging time can be shortened.

[0014] The control method of a charging device disclosed in the present invention is a control method of a charging device that charges a battery mounted on a vehicle.

[0015] The control method comprises the following steps:

[0016] obtaining the battery voltage, which is the voltage of the battery before charging of the battery is started; and

[0017] The output current value that can be output from the charging device is sent to the vehicle.

[0018] The outputtable current value is set so as to be smaller when the battery voltage is low than when the battery voltage is high.

[0019] According to this method, the battery voltage, which is the voltage of the battery before charging of the battery is started, is obtained, and the output current value that can be output from the charging device is sent to the vehicle. In addition, the output current value is set so that it is smaller when the battery voltage is low than when the battery voltage is high. Therefore, when the battery voltage is low, the output current value becomes smaller, so even when the output voltage of the charging device is lower than the lower limit voltage, the range that can be charged is expanded, and stable charging can be achieved.

[0020] The charging system disclosed in the present invention comprises:

[0021] A vehicle equipped with a battery capable of being externally charged;

[0022] Charging equipment that supplies charging power to the battery; and

[0023] A control device controls the charging device.

[0024] The control device is configured to transmit a value of an outputtable current that can be outputted from the charging facility to the vehicle.

[0025] The outputtable current value is set so as to be smaller when the voltage of the storage battery, that is, the battery voltage is low than when the battery voltage is high.

[0026] The vehicle sets a charging current command value based on the received outputtable current value, and transmits the charging current command value to the control device.

[0027] The control device controls the charging equipment so as to supply charging power to the battery based on the received charging current command value.

[0028] According to this structure, the control device of the charging system sends the output current value that can be output from the charging device to the vehicle. The vehicle sets the charging current command value based on the received output current value, and sends the charging current command value to the control device. The control device controls the charging device in a manner to supply charging power to the battery based on the received charging current command value. The output current value is set in a manner that is smaller when the battery voltage is low than when the battery voltage is high. For example, the lower the battery voltage, the smaller the output current value. Therefore, when the voltage of the battery being charged (battery voltage) is low, the output current value becomes smaller, so even if the output voltage of the charging device is lower than the lower limit voltage, the range that can be stably charged is expanded, and stable charging is possible.

[0029] According to the present disclosure, even when the output voltage of the charging equipment is lower than the lower limit voltage, stable charging is possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Features, advantages and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like numerals represent like elements, and in which:

[0031] Figure 1 is an overall structural diagram of the charging system of this embodiment;

[0032] Figure 2 is a timing chart showing an example of a charging start process executed in the ECU;

[0033] Figure 3 This is an example of mapping the maximum output power and the maximum output current;

[0034] Figure 4 is a timing chart showing an example of charging start processing in a modified example;

[0035] Figure 5 This is a flowchart showing an example of the during-charging process executed by the ECU. DETAILED DESCRIPTION

[0036] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, the same reference numerals are given to the same or corresponding parts in the drawings, and their description will not be repeated.

[0037] Figure 1 : is an overall structural diagram of the charging system 1 of the present embodiment. The charging system 1 includes a vehicle V and an electric vehicle supply equipment (EVSE) 400. In the present embodiment, the vehicle V is, for example, a battery electric vehicle (BEV) without an internal combustion engine. However, the present invention is not limited thereto, and the vehicle V may be a plug-in hybrid electric vehicle (PHEV) with an internal combustion engine, or may be another electric vehicle (electrified vehicle (xEV)).

[0038] The vehicle V includes a motor generator (MG) 10 as a rotating electrical machine, a power transmission gear 20 , drive wheels 30 , a power control unit (PCU) 40 , a system main relay (SMR) 50 , a battery 100 , a monitoring unit 200 , and an electronic control unit (ECU) 300 .

[0039] The MG 10 has a function as an electric motor and a function as a generator. The output torque of the MG 10 is transmitted to the drive wheels 30 via a power transmission gear 20 including a speed reducer and a differential device.

[0040] When the vehicle V is braked, the MG10 is driven by the drive wheel 30, and the MG10 operates as a generator. Thus, the MG10 also functions as a braking device for performing regenerative braking that converts the kinetic energy of the vehicle V into electric power. The regenerative electric power generated by the regenerative braking force in the MG10 is stored in the battery 100. The PCU 40 is a power conversion device that converts electric power bidirectionally between the MG10 and the battery 100. The SMR 50 is electrically connected to the power line that connects the battery 100 and the PCU 40. When the SMR 50 is closed (connected / ON), electric power is transferred between the battery 100 and the PCU 40.

[0041] The battery 100 stores electric power for driving the MG 10. The battery 100 is a rechargeable DC power source (secondary battery). The battery 100 is composed of, for example, a plurality of single batteries (battery cells) stacked and electrically connected in series.

[0042] Monitoring unit 200 includes a voltage sensor 210 that detects voltage VB of battery 100 , a current sensor 220 that detects current IB input to and output from battery 100 , and a temperature sensor 230 that detects temperature TB of battery 100 .

[0043] The ECU 300 includes a central processing unit (CPU) 301 and a memory (e.g., including a read-only memory (ROM), a random access memory (RAM), etc.) 302. The ECU 300 controls each device so that the vehicle V is in a desired state based on the signal received from the monitoring unit 200, the signal from various sensors (e.g., vehicle speed, accelerator opening, etc.), the map and program stored in the memory 302, and other information. For example, the ECU 300 calculates the state of charge (SOC) of the battery 100 based on the signal received from the monitoring unit 200, and controls the charging and discharging of the battery 100 using the SOC. In addition, the on / off state of the ignition switch (power switch) 250 is input to the ECU 300.

[0044] The vehicle V is provided with an inlet 60, which is configured to be connected to a connector 420 provided at the front end of a charging cable 410 of the EVSE 400. The connector 420 is connected to the inlet 60, and the charging relay (CHR) 70 is closed according to the instruction of the ECU 300, so that the external charging of the battery 100 can be performed. The EVSE 400 is provided with a power conversion circuit that converts the AC power supplied from the power system into DC power. The EVSE 400 is provided with an ECU 401 as a control device and a voltage sensor 402 that detects an output voltage. The ECU 401 includes a CPU and a memory, and controls the power output from the EVSE 400 (the charging power of the battery 100).

[0045] When power switch 250 is turned off and connector 420 of EVSE 400 is connected to inlet 60 , charging of storage battery 100 (external charging) starts.

[0046] Figure 2 4 is a timing chart showing an example of charging start processing executed in ECU 300 and 401. When connector 420 is connected to inlet 60, communication is established between ECU 401 and ECU 300. This communication may be controller area network (CAN) communication or power line communication (PLC) communication. In addition, the communication between ECU 401 and ECU 300 may also be short-range wireless communication.

[0047] When the communication between ECU 401 and ECU 300 is established, information exchange processing is performed (step 10, step 20 (hereinafter, steps are referred to as "S"). For example, the vehicle ID, charging voltage upper limit value CVmx, minimum current charging value, charging information, etc. are sent from the vehicle V (ECU 300) to the EVSE 400 (ECU 401). The identification ID, version, output voltage value SVmx, charging information, etc. are sent from the EVSE 400 (ECU 401) to the vehicle V (ECU 300).

[0048] When the information exchange process is completed and preparation for starting charging is completed in the vehicle V, the ECU 300 sends a preparation completion notification to the ECU 401 ( S21 ). Upon receiving the preparation completion notification from the ECU 300 , the ECU 401 performs insulation diagnosis and sends a completion notification to the ECU 300 if there is no abnormality ( S11 ).

[0049] When the vehicle V (ECU 300) receives the completion notification, it closes (turns on / ON) the CHR 70 (S22). After the EVSE 400 (ECU 401) sends the completion notification, it detects the voltage VB of the battery 100 through the voltage sensor 402 (S12). In addition, it is also possible to configure that the ECU 300 sends a CHR 70 turn-on notification, and the ECU 401 detects the voltage VB based on the voltage sensor 402 after receiving the turn-on notification. When the CHR 70 is in the closed state and the charging power is not output from the EVSE 400, the voltage detected by the voltage sensor 402 is the voltage VB of the battery 100.

[0050] The ECU 401 calculates the output power maximum value SWmx and the output current maximum value SImx based on the voltage VB detected by the voltage sensor 402 ( S13 ).

[0051] Figure 3 is an example of a mapping of the maximum output power SWmx and the maximum output current SImx. The mapping is stored in the memory of ECU 401. In S13, the maximum output power SWmx (see the dotted line) and the maximum output current SImx (see the solid line) are calculated based on the voltage VB using the mapping. Figure 3 As shown in FIG. 1 , the maximum output power SWmx and the maximum output current SImx are set so that when the voltage VB is low, they are smaller than when the voltage VB is high (the output is limited). In addition, the maximum output power SWmx and the maximum output current SImx may be set to smaller values ​​as the voltage VB is lower as shown by the single-dot chain line.

[0052] Refer again Figure 2ECU401 calculates the output current value Imax (S14). The output current value Imax is calculated using the calculation formula: "Output current value Imax = output power maximum value SWmx / min (charging voltage upper limit value CVmx, output voltage value SVmx)" (S14). min (charging voltage upper limit value CVmx, output voltage value SVmx) is the smaller value of the charging voltage upper limit value CVmx and the output voltage value SVmx.

[0053] When the outputtable current value Imax is greater than the output current maximum value SImx (affirmative determination in S15 ), the ECU 401 performs protection processing on the outputtable current value Imax with the output current maximum value SImx (in S16 , sets the outputtable current value Imax to the output current maximum value SImx).

[0054] Next, ECU 401 notifies the vehicle V (ECU 300) of the output current value Imax (S17). Upon receiving the output current value Imax, ECU 300 sets the charging current command value Ci. Then, ECU 300 sends the charging current command value Ci to ECU 401 to start the charging command (S23). The charging current command value Ci is a value less than the output current value Imax, and can be set, for example, according to the temperature TB of the battery 100.

[0055] When the ECU 401 receives the charging current command value Ci (when the charging command is issued), the EVSE 400 starts outputting charging power. The current value of the charging power output from the EVSE 400 is the charging current command value Ci. Thus, charging (external charging) of the battery 100 starts.

[0056] According to the present embodiment, the ECU 401 of the EVSE 400 transmits the output current value Imax that can be output from the EVSE 400 to the vehicle V (ECU 300). The output current value Imax is calculated using the calculation formula: "output current value Imax = output power maximum value SWmx / min (charging voltage upper limit value CVmx, output voltage value SVmx)". The output power maximum value SWmx is set to be smaller when the voltage VB of the battery 100 is low than when the voltage VB is high (refer to Figure 3 ). When the voltage VB of the battery 100 is low, the output current value Imax becomes small. Therefore, even if the output voltage of the EVSE 400 is lower than the lower limit voltage, the chargeable range is expanded, and stable charging is possible.

[0057] In the present embodiment, the maximum output current SImx is also set to be smaller when the voltage VB of the battery 100 is low than when the voltage VB is high (see Figure 3 ). The output current value Imax is protected by the output current maximum value SImx (see S15 and S16). Therefore, according to this structure, when the voltage VB of the battery 100 is low, the output current value Imax becomes small. Therefore, even if the output voltage of the EVSE 400 is lower than the lower limit voltage, the range in which charging can be performed is expanded, and stable charging can be performed.

[0058] In the present embodiment, the voltage VB used to calculate the maximum output power SWmx and the maximum output current SImx is the voltage of the storage battery 100 before the start of charging detected by the voltage sensor 402. The voltage VB before the start of charging is lower than the voltage VB after the start of charging. Therefore, the maximum output power SWmx and the maximum output current SImx can be suppressed from being unnecessarily increased, and as a result, the outputtable current value Imax can be suppressed from being increased, so that charging can be performed stably.

[0059] Modifications

[0060] Figure 4 4 is a timing chart showing an example of charging start processing in a modified example. In the above embodiment, the voltage VB before starting charging is detected using the voltage sensor 402 provided in the EVSE 400. In the modified example, after the communication between the ECU 401 and the ECU 300 is established, in the information exchange process, the EVSE 400 (ECU 401) calculates the output current value Imax and sends the output current value Imax to the ECU 300.

[0061] In the information exchange process (S10, S20) of the modified example, information including the charging voltage upper limit value CVmx and the lower limit voltage value VBmn is sent from the vehicle V (ECU300) to the EVSE400 (ECU401). The lower limit voltage value VBmn is the value of the normal lower limit voltage of the battery 100, which is set based on the specifications of the battery 100 and the vehicle V and stored in the memory 302 of the ECU300. The normal lower limit voltage of the battery 100 may be, for example, a voltage corresponding to the lower limit value of the SOC for stopping the normal travel of the vehicle V (stopping the discharge from the battery 100).

[0062] In the information exchange process of the modified example, the ECU 401 uses the received lower limit voltage value VBmn to calculate the maximum output power SWmx, the maximum output current SImx, and the output current value Imax (S13a to S16a). The processing of S13a to S16a is the same as the processing of S13 to S16, using the lower limit voltage value VBmn as the voltage VB, according to Figure 3The maximum output power SWmx and the maximum output current SImx are obtained by mapping (S13a). The output current Imax is obtained by using the calculation formula: "Output current value Imax = output power maximum value SWmx / min (charging voltage upper limit value CVmx, output voltage value SVmx)", and the protection process is performed with the maximum output current SImx (S14a to S16a). In addition to the identification ID, the ECU 401 also sends the calculated output current Imax to the ECU 300.

[0063] exist Figure 4 In the process of S21, S11, S22, S23 and S18, Figure 3 The same processing as S21, S11, S22, S23 and S18.

[0064] In this modification, in the vehicle V where the lower limit voltage value VBmn is low and the voltage VB of the battery 100 is low, the output current value Imax becomes smaller as in the above embodiment, so even if the output voltage of the EVSE 400 becomes lower than the lower limit voltage, the range that can be charged is expanded, and stable charging is possible.

[0065] In the above embodiment, the output current value Imax is calculated using the voltage VB before the start of charging. As the charging of the storage battery 100 progresses, the voltage VB rises. The charging current command value Ci is set to be less than the output current value Imax. Therefore, during the charging of the storage battery 100, the output current value Imax is reset in accordance with the rise in the voltage VB, so that the charging time can sometimes be shortened.

[0066] Figure 5 This is a flowchart showing an example of the processing during charging executed in ECU 401. During the charging of battery 100 (after the charging output starts in S18), this flowchart is repeatedly processed at predetermined intervals. For example, it is executed every time the offset learning of current sensor 220 of monitoring unit 200 is executed. When the offset learning is executed, the charging of battery 100 is temporarily stopped (the charging power becomes 0). In addition, during Figure 2 In S17 of the control unit 401 , the outputtable current value Imax notified to the ECU 300 is stored in the memory of the ECU 401 as the current value Imaxn.

[0067] exist Figure 5 In S30 , the voltage VB of the battery 100 is acquired. The voltage VB may be a value detected by the voltage sensor 402 , or may be a voltage VB detected by the voltage sensor 210 of the monitoring unit 200 .

[0068] In S31, the maximum output power SWmx and the maximum output current SImx are calculated based on the voltage VB obtained in S30. The processing of S31 is similar to that of S13 ( Figure 2 ) is the same. In S32, the output current value Imax is calculated, and in S33 and S34, the output current maximum value SImx is used to protect the output current value Imax. The processing of S32, 33, and 34 is the same as S14, 15, and 16 ( Figure 2 ) is the same, so its description is omitted.

[0069] In S35, it is determined whether the output current value Imax calculated in S31 to S34 is greater than the current value Imaxn stored in the memory by a predetermined value α or more. When the output current value Imax is greater than the current value Imaxn by a predetermined value α or more (Imax ≥ Imaxn + α), enter S36. When the output current value Imax is not greater than the current value Imaxn by a predetermined value α or more (Imax < Imaxn + α), the routine ends. The predetermined value α can be pre-set in consideration of the detection error of the voltage VB, etc., or alpha = 0.

[0070] In S36, after notifying ECU300 of the output current value Imax, the routine proceeds to S37. In S37, after storing the output current value Imax as the current value Imaxn in the memory of ECU401 (Imaxn←Imax), the routine ends. If ECU300 receives the output current value Imax, it resets the charging current command value Ci. The charging current command value Ci is a value below the output current value Imax, and can be reset according to the temperature TB of the battery 100, for example. When the charging current command value Ci is reset, the charging power corresponding to the reset charging current command value Ci is output from EVSE400.

[0071] By executing this charging process, the output current value Imax is regeneratively set based on the voltage VB during charging. When the voltage VB rises during charging, the output current value Imax increases, so the charging time can be shortened.

[0072] The embodiments disclosed this time should be considered in all respects as illustrative and non-restrictive. The scope of the present invention is indicated not by the description of the above embodiments but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A control device for a charging device, for charging a battery mounted on a vehicle, The control device is configured to transmit a current value that can be output from the charging facility to the vehicle, The outputtable current value is set to be smaller when the battery voltage, which is the voltage of the storage battery, is low than when the battery voltage is high.

2. The control device of the charging device according to claim 1, The battery voltage is the voltage of the storage battery before charging of the storage battery starts. The control device sets the outputtable current value before starting charging of the storage battery.

3. The control device for charging equipment according to claim 2, The control device resets the outputtable current value based on the battery voltage during charging of the storage battery.

4. A method for controlling a charging device, wherein the charging device charges a battery mounted on a vehicle, The control method comprises the following steps: obtaining a battery voltage which is a voltage of the battery before starting to charge the battery; and sending the output current value that can be output from the charging device to the vehicle, The outputtable current value is set to be smaller when the battery voltage is low than when the battery voltage is high.

5. A charging system comprising: A vehicle equipped with a battery capable of being externally charged; a charging device for supplying charging power to the battery; and A control device controls the charging device, The control device is configured to transmit a current value that can be output from the charging facility to the vehicle, The output current value is set so that when the voltage of the storage battery, that is, the battery voltage, is low, it is smaller than when the battery voltage is high. The vehicle sets a charging current command value based on the received outputtable current value, and transmits the charging current command value to the control device, The control device controls the charging facility so as to supply the charging power to the storage battery based on the received charging current command value.

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