Charging facility

Abstract

To provide a charging facility capable of effectively ensuring opportunities to use a power from a storage battery to suppress the maximum power consumption.SOLUTION: A charging facility according to the present disclosure supplies a charged power based on at least one of a power supplied from a power grid and a power discharged from a storage battery, to a battery mounted on a vehicle. A controller of the charging facility permits discharging from the storage battery when an SOC of the storage battery is a predetermined threshold value or more and the power supplied from the power grid is a discharging starting power or more, prohibits the discharging from the storage battery when the SOC of the storage battery is the threshold value or more and the power supplied from the power grid is less than a predetermined discharging stopping power which is less than or equal to the discharging starting power, and allows the storage battery to be charged by the power from the power grid so that the power supplied from the power grid does not exceed an upper limit value when the SOC of the storage battery is less than the threshold value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a charging facility used to charge a battery mounted on a vehicle. [Background technology]

[0002] A conventional charging system includes a charging unit connected to a power grid and supplying power to an onboard battery, a storage battery connected to the power grid and storing power for charging, a charging control unit that controls the amount of power supplied by the charging unit as charging power, and a discharging control unit that controls discharging of the storage battery (see, for example, Patent Document 1). The discharging control unit of this charging system reduces the amount of power discharged from the storage battery when it detects that the storage battery has reached a predetermined lower limit voltage or a predetermined stored power amount during discharging of the storage battery. The charging control unit also controls the amount of power supplied by the charging unit so that the amount of power discharged does not exceed a peak power amount calculated from the amount of power supply that the power grid can supply and the amount of power discharged by the storage battery. This prevents the power that would have been discharged from the storage battery from being supplied from the power grid when discharging from the storage battery is no longer supplied, making it possible to charge the onboard battery so that the maximum amount of power that the power grid can supply is not exceeded. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-099958 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the conventional charging system, if the system is used frequently, there may not be enough opportunities to charge the discharged storage battery, and the power from the storage battery may not be available to charge the vehicle battery. When the power from the storage battery is no longer available, the time required for each charge increases. Furthermore, if an attempt is made to shorten the charge time when the power from the storage battery is unavailable, the peak power (maximum power demand) increases, resulting in increased running costs for the charging system.

[0005] Therefore, a main object of the present disclosure is to provide a charging facility that can effectively secure opportunities to use power from a storage battery and suppress maximum power demand. [Means for solving the problem]

[0006] The charging equipment disclosed herein is a charging equipment that supplies charging power based on at least one of power supplied from a power grid and power discharged from a storage battery to a battery mounted on a vehicle, and includes a control device that allows discharge from the storage battery when the SOC of the storage battery is equal to or higher than a predetermined threshold and the power supplied from the power grid is equal to or higher than a predetermined discharge start power, prohibits discharge from the storage battery when the SOC of the storage battery is equal to or higher than the threshold and the power supplied from the power grid is equal to or lower than a predetermined discharge stop power that is equal to or lower than the discharge start power, and charges the storage battery with power from the power grid so that the power supplied from the power grid does not exceed a predetermined upper limit value when the SOC of the storage battery is less than the threshold.

[0007] The control device of the charging facility disclosed herein permits discharge from the storage battery when the SOC of the storage battery is equal to or greater than a predetermined threshold and the power supplied from the power grid is equal to or greater than a predetermined discharge start power. This allows the maximum power demand of the charging facility to be reduced by discharging from the storage battery. Furthermore, the control device prohibits discharge from the storage battery when the SOC of the storage battery is equal to or greater than a threshold and the power supplied from the power grid is equal to or less than a predetermined discharge stop power that is equal to or less than the discharge start power. This makes it possible to reduce a decrease in the SOC of the storage battery when the power supplied from the power grid is relatively low. Furthermore, when the SOC of the storage battery is below the threshold, the control device charges the storage battery with power from the power grid so that the power supplied from the power grid does not exceed a predetermined upper limit. This ensures the SOC of the storage battery and prevents the power from the storage battery from being unavailable to charge the vehicle battery. As a result, it is possible to effectively secure opportunities to use power from the storage battery and reduce the maximum power demand of the charging facility. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram showing a charging facility according to the present disclosure. [Figure 2] 4 is a flowchart illustrating a routine executed by a control device of the charging facility of the present disclosure. [Figure 3] 4 is a flowchart illustrating a routine executed by a control device of the charging facility of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] Next, embodiments of the present disclosure will be described with reference to the drawings.

[0010] 1 is a schematic diagram showing the configuration of a charging facility 1 according to the present disclosure. The charging facility 1 shown in the figure is a charging station capable of charging a battery 21 mounted on an electric vehicle 20, which may be a battery electric vehicle (BEV) or a plug-in hybrid vehicle (PHEV). In addition to the battery 21, which may be a lithium-ion secondary battery or a nickel-metal hydride secondary battery, the electric vehicle 20 includes a motor generator MG capable of outputting driving power and regenerative braking force, a charging inlet 22 connected to the battery 21 via a DC relay (not shown), an on-board communication device 23 capable of exchanging information with the charging facility 1, and an electronic control unit (hereinafter referred to as "ECU") 25 that executes various controls.

[0011] As shown in the figure, the charging facility 1 includes a power interruption unit 2 connected to a power system (commercial power system) 10 managed by a power company, a power line L1 connected to the power interruption unit 2, a power storage device 3 connected to the power interruption unit 2 via the power line L1, a plurality of chargers 4 (for example, three in this embodiment), and a control device 5 that controls the entire facility. The power interruption unit 2 is a main breaker that interrupts the circuit when the current from the power system 10 exceeds the contracted current (contracted power) contracted between the installer of the charging facility 1 and the power company.

[0012] The power storage device 3 includes a storage battery 30 having a higher rated voltage than the battery 21 of the electric vehicle 20, a power converter (AC / DC converter) 31, and an electronic control unit (ECU) 35. The power converter 31 is connected to the power line L1 via a relay (not shown), and when the relay is closed, converts AC power from the power grid 10 into DC power and supplies it to the storage battery 30. This makes it possible to charge the storage battery 30 using power from the power grid 10. The ECU 35 includes a computer having a CPU, ROM, RAM, etc. (not shown), and controls the opening and closing of the relay and the power converter 31. The ECU 35 also calculates the SOC (remaining capacity) of the storage battery 30 based on the terminal voltage, charge / discharge current, temperature, etc. of the storage battery 30.

[0013] Each of the chargers 4 is a DC quick charger connected to the power cutoff unit 2 via a power line L1 and to the storage battery 30 of the power storage device 3 via a power line L2, and is installed in a corresponding charging space in the charging facility 1. Each charger 4 is connected to the power line L1 via an AC relay and includes a power converter (AC / DC converter) that converts AC power from the power grid 10 to DC power when the AC relay is closed, and an electronic control unit (ECU) (both not shown). Furthermore, each charger 4 is connected to the power line L2 via a DC relay, and when the DC relay is closed, it can supply at least one of power from the power converter and power discharged from the storage battery 30 to the charging connector 4c via the charging cable.

[0014] As a result, when the charging connector 4c is connected to the charging inlet 22 of the electric vehicle 20, charging power based on at least one of the power supplied from the power grid 10 and the power discharged from the storage battery 30 can be supplied to the charging inlet 22 to charge the battery 21. The ECU of each charger 4 includes a computer having a CPU, ROM, RAM, etc. (not shown), and controls the opening and closing of the AC relay and the DC relay as well as the power converter. Furthermore, when the charging connector 4c is connected to the charging inlet 22 of the electric vehicle 20, the ECU of each charger 4 exchanges information with the ECU 25 via the on-board communication device 23 of the electric vehicle 20.

[0015] The control device 5 of the charging facility 1 includes a computer having a CPU, ROM, RAM, etc., not shown, a communication module, etc., and calculates the system supply power Ps, which is the power supplied from the power system 10, based on the detection values ​​of a current sensor and a voltage sensor, not shown. The control device 5 also exchanges information with the ECU 35 of the power storage device 3 and with the ECUs of each charger 4.

[0016] Next, the operation of the charging facility 1 will be described with reference to Figures 2 and 3. Figures 2 and 3 are flowcharts for explaining a routine that is repeatedly executed by the control device 5 at predetermined time intervals while the charging facility 1 is in operation.

[0017] 2 and 3, the control device 5 acquires the SOC of the storage battery 30 from the ECU 35 of the power storage device 3, and also acquires the separately calculated system supply power Ps supplied from the power grid 10 (step S100). Next, the control device 5 determines whether the SOC of the storage battery 30 acquired in step S100 is equal to or greater than a predetermined threshold (discharge allowance threshold) Sref (step S110). The threshold Sref used in step S110 is set within a range of 50-70%, for example, and is determined depending on the number of chargers 4 in the charging facility 1, etc.

[0018] When it is determined that the SOC of the storage battery 30 is equal to or greater than the threshold value Sref (step S110: YES), the control device 5 determines whether the grid-supplied power Ps acquired in step S100 is equal to or greater than a predetermined discharge start power P1 (step S120). The discharge start power P1, which serves as the threshold value used in step S120, is set to a value smaller than the contracted power contracted between the installer of the charging equipment 1 and the electric power company. When it is determined that the grid-supplied power Ps is equal to or greater than the discharge start power P1 (step S120: YES), the control device 5 turns on a discharge permission flag to permit discharging of the storage battery 30 (step S130) and temporarily ends the routine shown in FIG. 2 and other figures. As a result, when the discharge permission flag is turned on in step S120 and the charging connector 4c of at least one charger 4 is inserted into the charging inlet 22 of the electric vehicle 20, the DC relay of the charger 4 is closed, and charging power based on the power discharged from the storage battery 30 can be supplied to the battery 21 of the electric vehicle 20.

[0019] Furthermore, when the control device 5 determines that the grid supply power Ps is less than the discharge start power P1 (step S120: NO), the control device 5 determines whether the grid supply power Ps is equal to or less than a predetermined discharge stop power P2 (step S140). In this embodiment, the discharge stop power P2, which serves as a threshold used in step S140, is set to a value slightly smaller than the discharge start power P1. However, the discharge stop power P2 may be equal to the discharge start power P1. When the control device 5 determines that the grid supply power Ps is equal to or less than the discharge stop power P2 (step S140: YES), the control device 5 turns off the discharge permission flag to prohibit discharging of the storage battery 30 (step S150) and temporarily ends the routine shown in FIG. 2 and other figures. As a result, when the discharge permission flag is turned off in step S150 and the charging connector 4c of at least one charger 4 is inserted into the charging inlet 22 of the electric vehicle 20, the DC relay of the charger 4 is not closed, thereby disabling discharging of the storage battery 30. Furthermore, when it is determined that the system supply power Ps exceeds the discharge stop power P2 (step S140: NOS), the control device 5 temporarily ends the routine shown in FIG. 2 etc. without changing the setting of the discharge permission flag.

[0020] On the other hand, when it is determined that the SOC of the storage battery 30 is less than the threshold value Sref (step S110: YES), the control device 5 determines whether the grid supply power Ps acquired in step S100 is less than a predetermined upper limit value Plim (step S160), as shown in Fig. 3. The upper limit value Plim as a threshold value used in step S160 is set to a value slightly smaller than the contract power contracted between the installer of the charging facility 1 and the electric power company, and greater than the discharge start power P1.

[0021] When the control device 5 determines that the grid-supplied power Ps is less than the upper limit value Plim (step S160: YES), it turns on a charging permission flag to permit charging of the storage battery 30 (step S170). When the control device 5 determines that the grid-supplied power Ps is equal to or greater than the upper limit value Plim (step S160: NO), it turns off a charging permission flag to prohibit charging of the storage battery 30 (step S175). When the charging permission flag is turned on in step S170 and the storage battery 30 is not being charged, the ECU 35 of the power storage device 3 closes the relay of the power storage device 3 and controls the power converter 31 so that the storage battery 30 is charged with at least a portion of the grid-supplied power Ps. When the charging permission flag is turned on in step S170 and the storage battery 30 is being charged, the ECU 35 of the power storage device 3 continues charging of the storage battery 30 with at least a portion of the grid-supplied power Ps. Furthermore, when the charging permission flag is turned off in step S175 and the storage battery 30 is being charged, the ECU 35 of the power storage device 3 opens the relay of the power storage device 3 and stops the operation of the power converter 31. Also, when the charging permission flag is turned off in step S175 and the storage battery 30 is not being charged, the ECU 35 of the power storage device 3 keeps the relay of the power storage device 3 open and keeps the power converter 31 stopped.

[0022] After the processing of step S170 or S175, the control device 5 determines whether or not there is an unused charger 4 (step S180). If there is no unused charger 4 (step S180: NO), the control device 5 skips the subsequent processing and temporarily ends the routine shown in Fig. 3 etc. Furthermore, if there is an unused charger 4 (step S180: YES), the control device 5 acquires the charging power (zero if charging of the battery 21 is not being performed) supplied from the charger 4 to the battery 21 of the electric vehicle 20 from the charger 4, and acquires the charging power of the storage battery 30 (zero if charging is not being performed) from the ECU of each charger 4, and also acquires the charging power of the storage battery 30 from the ECU 35 of the power storage device 3 (step S190). Furthermore, in step S190, the control device 5 calculates the total charging power Psum, which is the sum of the charging power supplied from the multiple chargers 4 to the battery 21 of the electric vehicle 20 and the charging power of the storage battery 30.

[0023] The control device 5 then determines whether the total charging power Psum calculated in step S190 is equal to or less than a predetermined reference power Pref (step S200). The reference power Pref used as a threshold in step S200 is set to a value sufficiently smaller than the upper limit value Plim. If it is determined that the total charging power Psum is equal to or less than the reference power Pref (step S200: YES), the control device 5 turns on an additional charger use permission flag to permit the additional use of one unused charger 4 (step S210), and temporarily ends the routine shown in FIG. 3 etc. On the other hand, if the total charging power Psum exceeds the reference power Pref (step S200: NO), the control device 5 turns off an additional charger use permission flag to prohibit the additional use of an unused charger 4 (step S215), and temporarily ends the routine shown in FIG. 3 etc.

[0024] As described above, the charging facility 1 supplies charging power based on at least one of the power supplied from the power grid 10 and the power discharged from the storage battery 30 to the battery 21 mounted on the electric vehicle 20, and includes the control device 5 that executes the routines shown in Figures 2 and 3. The control device 5 permits discharge from the storage battery 30 (step S130) when the SOC of the storage battery 30 is equal to or greater than a predetermined threshold value Sref (step S110: YES) and the system supply power Ps supplied from the power grid 10 is equal to or greater than a predetermined discharge start power P1 (step S120: YES). This makes it possible to suppress the maximum power demand of the charging facility 1 by discharging from the storage battery 30, thereby suppressing an increase in the running costs of the charging facility 1.

[0025] Furthermore, when the SOC of the storage battery 30 is equal to or higher than the threshold value (step S110: YES) and the system supply power Ps supplied from the power system 10 is equal to or lower than a predetermined discharge stop power P2 that is equal to or lower than the discharge start power P1 (step S140: YES), the control device 5 prohibits discharge from the storage battery 30 (step S150). This makes it possible to suppress a decrease in the SOC of the storage battery 30 when the system supply power Ps from the power system 10 is relatively small.

[0026] Furthermore, when the SOC of the storage battery 30 is below the threshold value (step S110: NO), the control device 5 charges the storage battery 30 with the system-supplied power Ps from the power grid 10 so that the system-supplied power Ps does not exceed a predetermined upper limit value Plim (steps S160, S170, S175). This ensures the SOC of the storage battery 30 and prevents the power discharged from the storage battery 30 from becoming unavailable for charging the battery 21 of the electric vehicle 20. As a result, it is possible to effectively ensure opportunities to use the power from the storage battery 30 and suppress the maximum power demand of the charging facility 1.

[0027] Furthermore, the charging facility 1 includes a plurality of chargers 4 each capable of supplying charging power to the battery 21 of the electric vehicle 20, and the control device 5 permits the additional use of an unused charger 4, i.e., the simultaneous use of at least two chargers 4, when the total charging power Psum, which is the sum of the charging power supplied to the electric vehicle 20 and the charging power of the storage battery 30, is equal to or less than a predetermined reference power Pref. This makes it possible to further improve the availability of the charging facility 1 while suppressing the maximum power demand of the charging facility 1.

[0028] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present disclosure. Furthermore, the above-described embodiment is merely a specific form of the invention described in the Summary of the Invention, and does not limit the elements of the invention described in the Summary of the Invention. [Industrial Applicability]

[0029] The invention of the present disclosure can be used in the manufacturing industry of charging equipment and electric vehicles, etc. [Explanation of symbols]

[0030] 1 Charging equipment, 3 Energy storage device, 4 Charger, 4c Charging connector, 5 Control device, 10 Power system, 20 Electric vehicle, 21 Battery, 22 Charging inlet, 30 Storage battery, 31 Power converter, MG Motor generator.

Claims

[Claim 1] A charging facility that supplies charging power based on at least one of power supplied from a power grid and power discharged from a storage battery to a battery mounted on a vehicle, a control device that allows discharge from the storage battery when the SOC of the storage battery is equal to or greater than a predetermined threshold and the power supplied from the power grid is equal to or greater than a predetermined discharge start power, prohibits discharge from the storage battery when the SOC of the storage battery is equal to or greater than the threshold and the power supplied from the power grid is equal to or less than a predetermined discharge stop power that is equal to or less than the discharge start power, and charges the storage battery with power from the power grid so that the power supplied from the power grid does not exceed a predetermined upper limit value when the SOC of the storage battery is less than the threshold.

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