Control unit of charging equipment, control method of charging equipment, and charging system

Abstract

To provide a control unit of charging equipment capable of stably charging even when the output voltage of the charging equipment becomes lower than the lower limit voltage.SOLUTION: EVSE 400 (ECU 401) calculates the output maximum power value SWmx and output maximum current value SImx using the battery voltage VB before charging starts (S13). The maximum output power value SWmx and the maximum output current value SImx are set, when the voltage VB is low, to be smaller than when the voltage VB is high. The current value Imax capable of being output is calculated based on the maximum output power SWmx. The current value Imax capable of being output is set, when the voltage VB is low, to be smaller than when the voltage VB is high (S14).SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Japanese Patent Laid-Open Publication No. 2018-38198 (Patent Document 1) discloses a vehicle equipped with a power storage device that can be charged using an external power source. In this Patent Document 1, the power storage device is charged according to the command value that results in the smaller charging power between a charging current command value that is set according to the available output current of the charging station and a charging power command value that is set according to the required power of the vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-38198 A Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, information on the available output current of the charging station is provided from the charging station to the vehicle. When a part designed for a vehicle is converted into a part used in the charging station, the output voltage of the charging station may not meet the lower limit voltage of the specification value (design value) of the charging station. When the output voltage of the charging station becomes lower than the lower limit output voltage, the charging current output from the charging station may become smaller than the available output current by limiting the output to an acceptable level even at the low voltage. In this case, the charging current output from the charging station may deviate from the charging current command value, and charging may be stopped due to abnormal charging processing.

[0005] An object of the present disclosure is to enable stable charging even when the output voltage of a charging facility falls below a lower limit voltage. [Means for solving the problem]

[0006] The control device of the charging facility of the present disclosure is a control device of the charging facility that charges a battery mounted on a vehicle. The control device is configured to transmit an available output current value that can be output from the charging facility to the vehicle. The available output current value is set to be smaller when the battery voltage, which is the voltage of the battery, is low than when the battery voltage is high.

[0007] According to this configuration, the control device of the charging equipment transmits to the vehicle the available output current value that can be output from the charging equipment. The available output current value is set to be smaller when the battery voltage is low compared to when the battery voltage is high. For example, the lower the battery voltage, the smaller the available output current value. Therefore, when the voltage (battery voltage) of the battery to be charged is low, the available output current value becomes smaller, so that the charging range is expanded and stable charging becomes possible even if the output voltage of the charging equipment becomes lower than the lower limit voltage.

[0008] Preferably, the battery voltage may be a voltage of the battery before charging of the battery is started.The control device sets the available output current value before charging of the battery is started.

[0009] Generally, the battery voltage before charging starts is lower than the battery voltage after charging starts. Therefore, it is possible to prevent the outputtable current value from becoming unnecessarily large, and stable charging becomes possible. The battery voltage before charging starts may be detected by a voltage sensor provided in the charging equipment. Furthermore, when charging starts, information on the battery's normal lower limit voltage value may be transmitted from the vehicle before charging starts, and this normal lower limit voltage value may be used as the battery voltage before charging starts.

[0010] Preferably, the control device may reset the permissible output current value based on the battery voltage while the battery is being charged.

[0011] According to this configuration, the available output current value is reset based on the battery voltage during charging. When the battery voltage rises during charging, the available output current value increases, making it possible to shorten the charging time.

[0012] The present disclosure relates to a method for controlling charging equipment that charges a battery mounted on a vehicle. The method includes acquiring a battery voltage, which is the voltage of the battery before charging of the battery is started, and transmitting an available output current value that can be output from the charging equipment to the vehicle. The available output current value is set to be smaller when the battery voltage is low than when the battery voltage is high.

[0013] 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 available output current value that can be output from the charging equipment is transmitted to the vehicle. The available output current value is set to be smaller when the battery voltage is low than when the battery voltage is high. Therefore, when the battery voltage is low, the available output current value is smaller, so that the charging range is expanded and stable charging is possible even when the output voltage of the charging equipment becomes lower than the lower limit voltage.

[0014] The charging system of the present disclosure includes a vehicle equipped with an externally chargeable battery, a charging facility that supplies charging power to the battery, and a control device that controls the charging facility. The control device is configured to transmit an available output current value that can be output from the charging facility to the vehicle. The available output current value is set to be smaller when the battery voltage, which is the voltage of the battery, is low compared to when the battery voltage is high. The vehicle sets a charging current command value based on the received available output current value, and transmits the charging current command value to the control device. The control device controls the charging facility to supply charging power to the battery based on the received charging current command value.

[0015] According to this configuration, the control device of the charging system transmits to the vehicle an available output current value that can be output from the charging equipment. The vehicle sets a charging current command value based on the received available output current value and transmits the charging current command value to the control device. The control device controls the charging equipment to supply charging power to the battery based on the received charging current command value. The available output current value is set to be smaller when the battery voltage is low compared to when the battery voltage is high. For example, the lower the battery voltage, the smaller the available output current value. Therefore, when the voltage (battery voltage) of the battery to be charged is low, the available output current value becomes smaller, so that the range in which stable charging can be performed is expanded, and stable charging becomes possible even if the output voltage of the charging equipment becomes lower than the lower limit voltage. Effect of the Invention

[0016] According to the present disclosure, stable charging is possible even when the output voltage of the charging equipment falls below a lower limit voltage. [Brief description of the drawings]

[0017] [Figure 1] 1 is an overall configuration diagram of a charging system according to an embodiment of the present invention; [Diagram 2] 4 is a sequence illustrating an example of a charging start process executed in an ECU. [Diagram 3] 4 is an example of a map of maximum output power and maximum output current. [Figure 4] 10 is a sequence illustrating an example of a charging start process in a modified example. [Diagram 5] 5 is a flowchart showing an example of a charging process executed in the ECU. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and the description thereof will not be repeated.

[0019] 1 is an overall configuration diagram of a charging system 1 according to the present embodiment. The charging system 1 includes a vehicle V and charging equipment (EVSE: Electric Vehicle Supply Equipment) 400. In the present embodiment, the vehicle V is, for example, an electric vehicle (BEV: Battery Electric Vehicle) that does not have an internal combustion engine. However, the vehicle V is not limited to this, and may be a plug-in hybrid electric vehicle (PHEV: Plug-in Hybrid Electric Vehicle) that has an internal combustion engine, or may be another type of electric vehicle (xEV).

[0020] The vehicle V includes a motor generator (MG) 10, which is a rotating electric 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.

[0021] The MG 10 functions as both an electric motor (motor) and a generator. The output torque of the MG 10 is transmitted to drive wheels 30 via a power transmission gear 20 including a reduction gear, a differential gear, and the like.

[0022] When braking the vehicle V, the MG 10 is driven by the drive wheels 30 and operates as a generator. As a result, the MG 10 also functions as a braking device that performs regenerative braking to convert the kinetic energy of the vehicle V into electric power. Regenerative electric power generated by the regenerative braking force in the MG 10 is stored in the battery 100. The PCU 40 is a power conversion device that converts electric power in both directions between the MG 10 and the battery 100. The SMR 50 is electrically connected to a power line that connects the battery 100 and the PCU 40, and when the SMR 50 is closed (ON), electric power is exchanged between the battery 100 and the PCU 40.

[0023] The battery 100 stores power for driving the MG 10. The battery 100 is a rechargeable DC power supply (secondary battery), and is configured, for example, by stacking a plurality of single batteries (battery cells) and connecting them electrically in series.

[0024] The monitoring unit 200 includes a voltage sensor 210 that detects the voltage VB of the battery 100, a current sensor 220 that detects the current IB input to and output from the battery 100, and a temperature sensor 230 that detects the temperature TB of the battery 100.

[0025] The ECU 300 includes a CPU (Central Processing Unit) 301 and a memory (including, for example, a ROM (Read Only Memory) and a RAM (Random Access Memory)) 302. The ECU 300 controls each device so that the vehicle V is in a desired state based on information such as signals received from the monitoring unit 200, signals from various sensors (for example, vehicle speed, accelerator opening, etc.), and maps and programs stored in the memory 302. For example, the ECU 300 calculates a State of Charge (SOC) of the battery 100 based on a signal received from the monitoring unit 200, and controls charging and discharging of the battery 100 using this SOC. In addition, the ON / OFF state of an ignition switch (power switch) 250 is input to the ECU 300.

[0026] The vehicle V includes an inlet 60, to which a connector 420 provided at the tip of a charging cable 410 of the EVSE 400 can be connected. When the connector 420 is connected to the inlet 60 and a charging relay (CHR) 70 is closed by a command from the ECU 300, external charging of the battery 100 becomes possible. The EVSE 400 includes a power conversion circuit that converts AC power supplied from a power grid, for example, into DC power. The EVSE 400 includes an ECU 401 that is 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 (charging power for the battery 100).

[0027] When the power switch 250 is turned off and the connector 420 of the EVSE 400 is connected to the inlet 60, charging of the battery 100 (external charging) begins.

[0028] 2 is a sequence showing an example of a charging start process executed in the ECUs 300 and 401. When the connector 420 is connected to the inlet 60, communication is established between the ECU 401 and the ECU 300. This communication may be a controller area network (CAN) communication or a power line communication (PLC) communication. In addition, the communication between the ECU 401 and the ECU 300 may be short-range wireless communication.

[0029] When communication between ECU 401 and ECU 300 is established, information exchange processing is performed (steps 10 and 20 (hereinafter, step is abbreviated as "S")). For example, the vehicle V (ECU 300) transmits a vehicle ID, a charging voltage upper limit value CVmx, a minimum current charging value, billing information, etc. to EVSE 400 (ECU 401). The EVSE 400 (ECU 401) transmits an identification ID, a version, an available output voltage value SVmx, billing information, etc. to vehicle V (ECU 300).

[0030] When the information exchange process is completed and preparations to start charging are completed in the vehicle V, the ECU 300 transmits a preparation completion notification to the ECU 401 (S21). Upon receiving the preparation completion notification from the ECU 300, the ECU 401 performs an insulation diagnosis, and if no abnormality is found, transmits a completion notification to the ECU 300 (S11).

[0031] Upon receiving the completion notification, the vehicle V (ECU 300) closes (ON) the CHR 70 (S22). After transmitting the completion notification, the EVSE 400 (ECU 401) detects the voltage VB of the battery 100 using the voltage sensor 402 (S12). Note that the ECU 300 may be configured to transmit an ON notification of the CHR 70, and the ECU 401 may detect the voltage VB using the voltage sensor 402 after receiving the ON notification. When the CHR 70 is in the closed state and charging power is not being output from the EVSE 400, the voltage detected by the voltage sensor 402 is the voltage VB of the battery 100.

[0032] The ECU 401 calculates a maximum output power value SWmx and a maximum output current value SImx based on the voltage VB detected by the voltage sensor 402 (S13).

[0033] 3 is an example of a map of maximum output power SWmx and maximum output current SImx. This map is stored in the memory of ECU 401. In S13, this map is used to calculate maximum output power SWmx (see dashed line) and maximum output current SImx (see solid line) based on voltage VB. As shown in FIG. 3, maximum output power SWmx and maximum output current SImx are set to be smaller (output is limited) when voltage VB is low compared to when voltage VB is high. Note that maximum output power SWmx and maximum output current SImx may be set to be smaller as voltage VB is lower, as shown by dashed line.

[0034] 2 again, ECU 401 calculates available output current value Imax (S14). Available output current value Imax is calculated using the formula: available output current value Imax=maximum output power value SWmx / min (upper charge voltage value CVmx, available output voltage value SVmx) (S14). min (upper charge voltage value CVmx, available output voltage value SVmx) is the smaller of upper charge voltage value CVmx and available output voltage value SVmx.

[0035] When the available output current value Imax is greater than the maximum output current value SImx (when a positive judgment is made in S15), the ECU 401 guards the available output current value Imax with the maximum output current value SImx (in S16, the available output current value Imax is set to the maximum output current value SImx).

[0036] Next, the ECU 401 notifies the vehicle V (ECU 300) of the available output current value Imax (S17). Upon receiving the available output current value Imax, the ECU 300 sets a charging current command value Ci. Then, the ECU 300 transmits the charging current command value Ci to the ECU 401 and starts a charging command (S23). The charging current command value Ci is a value equal to or less than the available output current value Imax, and may be set according to the temperature TB of the battery 100, for example.

[0037] When the ECU 401 receives the charging current command value Ci (when a charging command is started), it starts outputting charging power from the EVSE 400. The current value of the charging power output from the EVSE 400 is the charging current command value Ci. This starts charging the battery 100 (external charging).

[0038] According to this embodiment, the ECU 401 of the EVSE 400 transmits the available output current value Imax that can be output from the EVSE 400 to the vehicle V (ECU 300). The available output current value Imax is calculated using the formula: "available output current value Imax = maximum output power value SWmx / min (upper charge voltage value CVmx, available output voltage value SVmx)". The maximum output power value SWmx is set to be smaller when the voltage VB of the battery 100 is low than when the voltage VB is high (see FIG. 3). When the voltage VB of the battery 100 is low, the available output current value Imax is smaller, so that the range in which charging can be performed is expanded and stable charging can be performed even if the output voltage of the EVSE 400 becomes lower than the lower limit voltage.

[0039] In this embodiment, the maximum output current value 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 FIG. 3). Since the available output current value Imax is guarded by the maximum output current value SImx (see S15, S16), even with this configuration, when the voltage VB of the battery 100 is low, the available output current value Imax is small. This widens the range in which charging can be performed, enabling stable charging, even if the output voltage of the EVSE 400 becomes lower than the lower limit voltage.

[0040] In this embodiment, the voltage VB for calculating the maximum output power SWmx and the maximum output current SImx is the voltage of the battery 100 before charging starts, detected by the voltage sensor 402. The voltage VB before charging starts is lower than the voltage VB after charging starts. Therefore, the maximum output power SWmx and the maximum output current SImx can be prevented from becoming unnecessarily large, and as a result, the maximum output current value Imax can be prevented from becoming large, making it possible to charge stably.

[0041] (Modification) 4 is a sequence showing an example of a charging start process in the modified example. In the above embodiment, the voltage VB before the start of charging is detected by the voltage sensor 402 provided in the EVSE 400. In the modified example, after communication between the ECU 401 and the ECU 300 is established, the EVSE 400 (ECU 401) calculates the available output current value Imax and transmits it to the ECU 300 in the information exchange process.

[0042] In the information exchange process (S10, 20) of the modified example, information including the charging voltage upper limit value CVmx and the lower limit voltage value VBmn is transmitted from the vehicle V (ECU 300) to the EVSE 400 (ECU 401). The lower limit voltage value VBmn is a value of a normal lower limit voltage of the battery 100, which is set based on the specifications of the battery 100 and the vehicle V, and is stored in the memory 302 of the ECU 300. The normal lower limit voltage of the battery 100 may be, for example, a voltage corresponding to a lower limit value of the SOC at which normal traveling of the vehicle V is stopped (discharge from the battery 100 is stopped).

[0043] 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 available output current value Imax (S13a to S16a). The process of S13a to S16a is the same as the process of S13 to S16, and the lower limit voltage value VBmn is used as the voltage VB, and the maximum output power SWmx and the maximum output current SImx are obtained from the map of FIG. 3 (S13a). The available output current value Imax is obtained using the calculation formula: "available output current value Imax = maximum output power SWmx / min (upper charge voltage value CVmx, available output voltage value SVmx)", and guard process is performed with the maximum output current SImx (S14a to S16a). Then, the ECU 401 transmits the calculated available output current value Imax to the ECU 300 in addition to the identification ID and the like.

[0044] In FIG. 4, the processes of S21, S11, S22, S23, and S18 are similar to the processes of S21, S11, S22, S23, and S18 in FIG.

[0045] Even in this modified example, in a vehicle V in which the lower limit voltage value VBmn is low and the voltage VB of the battery 100 is low, the outputtable current value Imax becomes small, as in the above embodiment, so that even if the output voltage of the EVSE 400 becomes lower than the lower limit voltage, the range in which charging can be performed is expanded and stable charging becomes possible.

[0046] In the above embodiment, the available output current value Imax is calculated using the voltage VB before the start of charging. As charging of the battery 100 progresses, the voltage VB increases. The charging current command value Ci is set to be equal to or lower than the available output current value Imax. Therefore, by resetting the available output current value Imax in accordance with the increase in the voltage VB while charging the battery 100, it may be possible to shorten the charging time.

[0047] FIG. 5 is a flowchart showing an example of the charging process executed in the ECU 401. This flowchart is repeatedly processed at predetermined intervals during charging of the battery 100 (after the start of charging output in S18). For example, it is executed every time offset learning of the current sensor 220 of the monitoring unit 200 is performed. When offset learning is executed, charging of the battery 100 is temporarily stopped (charging power becomes 0). Note that the output possible current value Imax notified to the ECU 300 in S17 of FIG. 2 is stored in the memory of the ECU 401 as the current value Imaxn.

[0048] In FIG. 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 the voltage VB detected by the voltage sensor 210 of the monitoring unit 200.

[0049] In S31, based on the voltage VB acquired in S30, the maximum output power SWmx and the maximum output current SImx are calculated. The process of S31 is the same as that of S13 (FIG. 2). In S32, the output possible current value Imax is calculated, and in S33 and S34, the output possible current value Imax is guarded by the maximum output current SImx. Since the processes of S32, S33, and S34 are the same as the processes of S14, S15, and S16 (FIG. 2), the description thereof is omitted.

[0050] In S35, it is determined whether or not the output possible current value Imax calculated in S31 to S34 is greater than or equal to a predetermined value α than the current value Imaxn stored in the memory. When the output possible current value Imax is greater than or equal to the predetermined value α than the current value Imaxn (Imax ≧ Imaxn + α), the process proceeds to S36. When the output possible current value Imax is not greater than or equal to the predetermined value α than the current value Imaxn (Imax < Imaxn + α), the current routine ends. The predetermined value α may be set in advance in consideration of the detection error of the voltage VB or the like, and α = 0 may also be used.

[0051] In S36, the available output current value Imax is notified to the ECU 300, and then the process proceeds to S37. In S37, the available output current value Imax is stored in the memory of the ECU 401 as a current value Imaxn (Imaxn←Imax), and the current routine ends. When the ECU 300 receives the available output current value Imax, it resets the charging current command value Ci. The charging current command value Ci is a value equal to or less than the available output current value Imax, and may be reset, for example, in accordance with the temperature TB of the battery 100. When the charging current command value Ci is reset, the EVSE 400 outputs charging power in accordance with the reset charging current command value Ci.

[0052] By executing this charging process, the available output current value Imax is regenerated and set based on the voltage VB during charging. When the voltage VB rises during charging, the available output current value Imax becomes larger, making it possible to shorten the charging time.

[0053] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not by the description of the embodiments described above, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0054] 1 charging system, 10 motor generator (MG), 20 drive transmission gear, 30 drive wheel, 40 PCU, 50 SMR, 60 inlet, 70 CHR, 100 battery, 200 monitoring unit, 210 voltage sensor, 220 current sensor, 250 ignition switch, 300 ECU, 301 CPU, 302 memory, 400 EVSE, 401 ECU, 402 voltage sensor, 420 connector, V vehicle.

Claims

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

2. the battery voltage is a voltage of the battery before charging of the battery is started; The control device for a charging facility according to claim 1 , wherein the control device sets the permissible output current value before starting charging of the battery.

3. The charging facility control device according to claim 2 , wherein the control device resets the permissible output current value based on the battery voltage while the battery is being charged.

4. A method for controlling charging equipment that charges a battery mounted on a vehicle, comprising: Obtaining a battery voltage, which is a voltage of the battery before starting charging of the battery; transmitting an available output current value that can be output from the charging facility to the vehicle; A method for controlling charging equipment, wherein the available output current value is set to be smaller when the battery voltage is low compared to when the battery voltage is high.

5. A vehicle equipped with an externally chargeable battery; A charging facility for supplying charging power to the battery; A control device that controls the charging facility, The control device is configured to transmit, to the vehicle, an available output current value that can be output from the charging facility, the available output current value is set to be smaller when a battery voltage, which is a voltage of the battery, is low than when the battery voltage is high; the vehicle sets a charging current command value based on the received available output current value, and transmits the charging current command value to the control device; The control device controls the charging equipment so as to supply the charging power to the battery based on the received charging current command value.

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