Charging system

Abstract

To provide a charging system which includes a plurality of chargers and can suppress concentration of power consumption.SOLUTION: A charging system A1 comprises: a plurality of chargers 2 for charging an accumulator 54 of an electric vehicle 5; and a charge control device 1 for controlling the plurality of chargers 2. The charge control device 1 comprises: a tolerable power acquisition unit 111 for acquiring a tolerable power value being a tolerable maximum value of a total value of output power of the plurality of chargers 2; a connection detection unit 112 for detecting a connection charger connected with the electric vehicle 5 among the plurality of chargers 2; a current setting unit 113 for setting each of set current values being current values for setting output current of one or a plurality of connection chargers based on a result of detection by the connection detection unit 112 and the tolerable power value; and a communication unit 12 for transmitting each set current value to a corresponding connection charger. Each connection charger 2 transmits a signal dependent on a received set current value to a connected electric vehicle 5.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a charging system comprising multiple ordinary charging devices for charging electric vehicles and the like. [Background technology]

[0002] In recent years, with the spread of electric vehicles, the development of charging stations for charging the batteries of electric vehicles has progressed. Patent Document 1 discloses a so-called standard charging device. The standard charging device communicates with the electric vehicle using a CPLT signal. The standard charging device transmits the maximum current value that can be supplied to the electric vehicle based on the duty cycle of the CPLT signal. As a result, the standard charging device can charge the electric vehicle without exceeding the maximum current value according to its own specifications. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] WO2018 / 061857 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, in facilities equipped with numerous standard charging stations, if multiple electric vehicles are connected to each station and charged simultaneously, power consumption becomes concentrated. In this case, the maximum demand increases, exceeding the contracted power capacity and resulting in higher electricity bills. To prevent this, installing a demand control device at each standard charging station would increase implementation costs.

[0005] The present invention was conceived under the circumstances described above, and its purpose is to provide a charging system that includes multiple charging devices and can suppress the concentration of power consumption. [Means for solving the problem]

[0006] To solve the above problems, the present invention employs the following technical means.

[0007] A charging system provided by a first aspect of the present invention comprises a plurality of charging devices for charging the battery of an electric mobile vehicle that moves by driving an electric motor with the power of the battery, and a charging control device for controlling the plurality of charging devices, wherein the charging control device comprises an allowable power acquisition unit for acquiring an allowable power value which is the maximum allowable value of the total output power of the plurality of charging devices, a connection detection unit for detecting a connected charging device among the plurality of charging devices to which the electric mobile vehicle is connected, a current setting unit for setting a set current value which is a current value for setting the output current of each connected charging device based on the detection result by the connection detection unit and the allowable power value, and a communication unit for transmitting each set current value to the corresponding connected charging device, wherein each connected charging device transmits a signal corresponding to the received set current value to the connected electric vehicle.

[0008] Furthermore, "electric mobile vehicles" refer to mobile vehicles that move by driving an electric motor with power from a storage battery, and include not only so-called electric vehicles but also hybrid vehicles. In addition, "electric mobile vehicles" include not only so-called automobiles but also other vehicles such as motorcycles, ships, and airplanes, as well as unmanned mobile vehicles such as automated guided vehicles and drones.

[0009] In a preferred embodiment of the present invention, the current setting unit sets each of the setting current values ​​to a current value that is less than or equal to the power value obtained by dividing the allowable power value by the number of connected charging devices detected by the connection detection unit.

[0010] In a preferred embodiment of the present invention, the charging control device further comprises a coefficient acquisition unit that acquires a weighting coefficient set for each of the connected charging devices detected by the connection detection unit, and the current setting unit sets each of the set current values ​​to a current value less than or equal to a power value corresponding to the allowable power value allocated according to the weighting coefficient.

[0011] In a preferred embodiment of the present invention, the charging control device further comprises a current acquisition unit that acquires a detected current value by detecting the output current of each charging device, and the current setting unit resets the detected current value as the set current value when the detected current value of each connected charging device is less than or equal to a predetermined value than the corresponding set current value, and recalculates and resets the set current value for connected charging devices in which the detected current value is greater than the value obtained by subtracting the predetermined value from the corresponding set current value.

[0012] In a preferred embodiment of the present invention, the allowable power acquisition unit acquires the allowable power value from a higher-level device that performs energy management. [Effects of the Invention]

[0013] According to the present invention, the current setting unit of the charging control device sets the set current value for each connected charging device based on the detection result by the connection detection unit and the allowable power value. The communication unit then transmits each set current value to the corresponding connected charging device, and each connected charging device transmits a signal to the electric vehicle corresponding to the received set current value. The electric vehicle charges the battery based on the set current value. Therefore, the charging system according to the present invention prevents the use of power exceeding the allowable power value and can suppress the concentration of power consumption.

[0014] Other features and advantages of the present invention will become more apparent from the detailed description below with reference to the accompanying drawings. [Brief explanation of the drawing]

[0015] [Figure 1] This is a block diagram showing the overall configuration of the charging system according to the first embodiment. [Figure 2] This is a timing chart to explain the CPLT signal. [Figure 3] This is an example of a flowchart illustrating the current setting process performed by the control unit. [Figure 4] This is a time chart to explain the set current values ​​in response to changes in the number of connections and the allowable power value. [Figure 5] It is a diagram for explaining the charging system according to the second embodiment. [Figure 6] It is a diagram for explaining the charging system according to the third embodiment.

Mode for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

[0017] 〔First Embodiment〕 FIG. 1 is a diagram for explaining a charging system A1 according to the first embodiment. FIG. 1(a) is a block diagram showing the overall configuration of the charging system A1. FIG. 1(b) is a block diagram showing the internal configurations of the charging device 2 and the electric vehicle 5.

[0018] The charging system A1 is equipment for charging the electric vehicle 5. The electric vehicle 5 is an automobile equipped with an electric motor as a power source and a storage battery 54 that supplies power to the electric motor, and includes not only a so-called electric vehicle that uses only the electric motor as a power source, but also a hybrid vehicle equipped with an internal combustion engine. The charging system A1 includes a charging control device 1 and a plurality of charging devices 2.

[0019] Multiple charging devices 2 are arranged in a parking lot or similar location to charge the electric vehicle 5. The charging devices 2 are so-called ordinary charging devices, and charge the battery 54 of the electric vehicle 5 using single-phase AC power from the commercial power supply 9. In this embodiment, we will describe the case in which the charging system A1 is equipped with five charging devices 2a to 2e. Note that the number of charging devices 2 equipped in the charging system A1 is not limited. In this embodiment, each of the five charging devices 2a to 2e in the charging system A1 is connected to the electric vehicle 5 by a charging connector 25c located at the end of the charging cable 25, which is connected to the plug-in connector 55 of the electric vehicle 5. As shown in Figure 1(b), the charging cable 25 is equipped with a signal line 25a and a power line 25b. The signal line 25a transmits and receives CPLT (Control Pilot) signals between the charging device 2 and the electric vehicle 5. The power line 25b transmits power from the charging device 2 to the electric vehicle 5.

[0020] As shown in Figure 1(b), the charging device 2 includes a control unit 21, a communication unit 22, a CPLT control unit 23, and an opening / closing unit 24.

[0021] The communication unit 22 communicates with the charging control device 1. The communication unit 22 communicates bidirectionally with the charging control device 1 via a communication line. The communication unit 22 may also communicate with the charging control device 1 via wireless communication. The communication standard is not limited. The communication unit 22 receives a set current value from the charging control device 1 and outputs it to the control unit 21. The set current value is the current value used to set the output current of the charging device 2 and is calculated by the charging control device 1. The communication unit 22 also receives a signal from the control unit 21 indicating the connection status of the electric vehicle 5 and transmits it to the charging control device 1. The information transmitted and received between the communication unit 22 and the charging control device 1 is not limited. The switching unit 24 switches the conductive path from the commercial power supply 9 to the power line 25b between a closed state (on) and an open state (off) in response to a command from the control unit 21. The switching unit 24 is, for example, a relay switch, but is not limited.

[0022] The CPLT control unit 23 generates a CPLT signal based on the international standard IEC (61851-1). The CPLT control unit 23 outputs the CPLT signal to the electric vehicle 5 connected to the charging cable 25 via the signal line 25a located on the charging cable 25. The CPLT signal is a control signal that indicates the connection status of the charging cable 25, the start and end of charging, and the setting current value by changing the voltage and pulse width. Details of the CPLT signal will be described later.

[0023] The control unit 21 is configured to control the charging device 2 and is implemented, for example, by a microcomputer. The control unit 21 receives a set current value from the charging control device 1 via the communication unit 22 and outputs it to the CPLT control unit 23. The control unit 21 also detects the connection status of the electric vehicle 5 according to the voltage of the CPLT signal detected by the CPLT control unit 23 and transmits it to the charging control device 1 via the communication unit 22. Furthermore, the control unit 21 outputs an open / close command to the open / close unit 24 according to the voltage of the CPLT signal detected by the CPLT control unit 23.

[0024] As shown in Figure 1(b), the electric vehicle 5 includes a control unit 51, a power conversion unit 52, a CPLT control unit 53, and a storage battery 54.

[0025] The power conversion unit 52 converts the AC power supplied from the charging device 2 via the power line 25b to charge the storage battery 54. The power conversion unit 52 includes, for example, a rectifier circuit, a DC / DC converter circuit, and a charging circuit (not shown). The rectifier circuit converts the AC power supplied from the charging device 2 into DC power. The DC / DC converter circuit boosts the DC voltage input from the rectifier circuit to the voltage required to charge the storage battery 54 and outputs it. The charging circuit controls the current output to the storage battery 54 to a set current value input from the control unit 51. The specific configuration of the power conversion unit 52 is not limited.

[0026] The CPLT control unit 53 inputs and outputs CPLT signals to and from the charging device 2 via the signal line 25a. The CPLT control unit 53 also changes the voltage of the CPLT signal by switching the connection of an internally placed resistor (not shown) to change its resistance value in response to instructions from the control unit 51. The CPLT control unit 53 also receives a set current value based on the CPLT signal and outputs it to the control unit 51.

[0027] The control unit 51 controls the charging of the battery 54 of the electric vehicle 5 and is implemented by, for example, a microcomputer. The control unit 51 outputs a set current value input from the CPLT control unit 53 to the power conversion unit 52. The control unit 51 also detects the connection status of the electric vehicle 5 according to the voltage of the CPLT signal detected by the CPLT control unit 53. The control unit 51 also instructs the CPLT control unit 53 to change the voltage of the CPLT signal.

[0028] Figure 2 is a time chart illustrating the CPLT signal. Figure 2(a) shows the time variation of the set current value received by the charging device 2 from the charging control device 1. Figure 2(b) shows the time variation of the CPLT signal input and output between the CPLT control unit 23 and the CPLT control unit 53. Figure 2(c) shows the time variation of the state of the switching unit 24. Figure 2(d) shows the time variation of the charging current input to the storage battery 54.

[0029] At time t0, the charging device 2 is started up, power is supplied to the CPLT control unit 23, and the CPLT control unit 23 outputs a CPLT signal with voltage V1 (e.g., 12V). At time t1, the charging connector 25c of the charging cable 25 is connected to the plug-in connector 55 of the electric vehicle 5. As a result, the voltage of the CPLT signal drops to V2 (e.g., 9V) according to the voltage division ratio between the resistor (not shown) connected in series with the signal line 25a in the CPLT control unit 23 and the resistor (not shown) connected in parallel with the signal line 25a in the CPLT control unit 53. Based on the voltage of the CPLT signal detected by the CPLT control unit 23, the control unit 21 can detect that the charging device 2 and the electric vehicle 5 are connected. When the control unit 21 detects the connection between the charging device 2 and the electric vehicle 5 (a drop in the CPLT signal voltage), it transmits a connection detection signal to the charging control device 1 via the communication unit 22. Upon receiving the connection detection signal, the charging control device 1 transmits a set current value to the charging device 2. The method by which the charging control device 1 sets the set current value will be described later.

[0030] At time t2, the set current value received from the charge control device 1 changes to I1. Then, from time t3, the CPLT control unit 23 generates an AC signal with a duty cycle corresponding to the set current value (I1) and outputs it as a CPLT signal. The CPLT control unit 53 detects the set current value (I1) based on the duty cycle of the CPLT signal and outputs it to the control unit 51. The control unit 51 outputs the input set current value (I1) to the power conversion unit 52. The power conversion unit 52 controls the current output to the storage battery 54 based on the input set current value (I1).

[0031] After the CPLT control unit 53 detects the set current value (I1), it changes the resistance value of the parallel-connected resistor, causing the CPLT signal voltage to drop to V3 (e.g., 6V) at time t4. When the control unit 21 detects the voltage drop in the CPLT signal, it switches the switching unit 24 from off to on (time t5), starting to supply power to the electric vehicle 5. As a result, the charging current to the storage battery 54 changes from "0" to I1.

[0032] At time t6, the set current value received by the communication unit 22 from the charge control device 1 changes to I2. Then, from time t7, the CPLT control unit 23 generates an AC signal with a duty cycle corresponding to the set current value (I2) and outputs it as a CPLT signal. The CPLT control unit 53 detects the set current value (I2) based on the duty cycle of the CPLT signal and outputs it to the control unit 51. The control unit 51 outputs the input set current value (I2) to the power conversion unit 52. The power conversion unit 52 controls the current output to the storage battery 54 based on the input set current value (I2). As a result, the charging current to the storage battery 54 changes from I1 to I2.

[0033] Subsequently, when the set current value received by the communication unit 22 from the charging control device 1 changes, the CPLT control unit 23 generates an AC signal with a duty cycle corresponding to the set current value and outputs it as a CPLT signal. The CPLT control unit 53 detects the set current value based on the duty cycle of the CPLT signal, and the power conversion unit 52 controls the current output to the storage battery 54 based on the detected set current value. As described above, the charging device 2 instructs the electric vehicle 5 using the CPLT signal with the set current value received from the charging control device 1.

[0034] Although not shown in Figure 2, once charging is complete, the CPLT control unit 53, at the instruction of the control unit 51, raises the voltage of the CPLT signal to V2. When the control unit 21 detects the rise in the CPLT signal voltage, it switches the switching unit 24 from on to off to stop the power supply to the electric vehicle 5. Subsequently, when the connection of the charging cable 25 is released, the voltage of the CPLT signal rises to V1. Based on the voltage of the CPLT signal, the control unit 21 can detect that the connection between the charging device 2 and the electric vehicle 5 has been released. When the control unit 21 detects the release of the connection between the charging device 2 and the electric vehicle 5 (rise in CPLT signal voltage), it transmits a release detection signal to the charging control device 1 via the communication unit 22.

[0035] The charging control device 1 controls the charging of multiple charging devices 2. The charging control device 1 detects whether an electric vehicle 5 is connected to each charging device 2, calculates the set current value for the charging device 2 to which the electric vehicle 5 is connected, and transmits it. The charging control device 1 includes a control unit 11 and a communication unit 12.

[0036] The communication unit 12 performs bidirectional communication with each charging device 2 via a communication line. Note that communication between the communication unit 12 and the communication unit 22 may be wireless communication. The communication unit 12 receives connection detection signals and disconnection detection signals from each charging device 2 and outputs them to the control unit 11. The communication unit 12 also transmits the set current value for each charging device 2 calculated by the control unit 11 to the corresponding charging device 2. Note that the information transmitted and received between the communication unit 12 and the communication unit 22 is not limited.

[0037] The control unit 11 controls the charging control device 1 and is implemented by, for example, a microcomputer. The control unit 11 controls communication by the communication unit 12. The control unit 11 also determines the connection status of each charging device 2 from the connection detection signal and disconnection detection signal input from the communication unit 12. The control unit 11 then calculates the set current value for each charging device 2 based on the allowable power value, which is the maximum power that the charging system A1 is allowed to use (i.e., the maximum allowable total value of the output power of the multiple charging devices 2). The control unit 11 has a functional configuration that includes an allowable power acquisition unit 111, a connection detection unit 112, and a current setting unit 113.

[0038] The allowable power acquisition unit 111 is a functional configuration for acquiring the allowable power value. In this embodiment, the allowable power acquisition unit 111 acquires the allowable power value input from the higher-level device 8. Alternatively, the allowable power acquisition unit 111 may acquire the allowable power value based on the allowable value set in the circuit breaker installed in the charging system A1. The allowable power acquisition unit 111 outputs the acquired allowable power value to the current setting unit 113.

[0039] The higher-level device 8 is a device that manages the energy of the charging system A1 (each charging device 2) and other equipment (not shown) installed in the facility. This equipment includes, for example, a power generation system such as a solar power generation system, an energy storage system equipped with batteries for storing electricity, and various loads installed in the facility. The higher-level device 8 detects the total power used in the facility and controls each piece of equipment so that the demand value, which is the average power usage over a 30-minute period (demand time), does not exceed the contracted power. The higher-level device 8 changes the allowable power value output to the charging control device 1 according to the demand value. In this case, the charging system A1 can contribute to energy management. Alternatively, the higher-level device 8 may also change the allowable power value based on the power company's supply capacity and power usage forecasts for different time periods. In this case, the charging system A1 can also contribute to responding to power supply and demand shortages.

[0040] The connection detection unit 112 is configured to detect which of the multiple charging devices 2 is connected to the electric vehicle 5. Based on the connection detection signal and disconnection detection signal input from each charging device 2 via the communication unit 12, the connection detection unit 112 determines whether or not the electric vehicle 5 is connected to each charging device 2. The connection detection unit 112 determines that the electric vehicle 5 is connected to a charging device 2 that is outputting a connection detection signal, and that the electric vehicle 5 is not connected to a charging device 2 that is outputting a disconnection detection signal. The connection detection unit 112 may also detect which charging device 2 is connected to the electric vehicle 5 by other means. In this embodiment, the connection detection unit 112 detects the number of connections, which is the number of charging devices 2 to which the electric vehicle 5 is connected, and outputs the detected number of connections to the current setting unit 113.

[0041] The current setting unit 113 is a functional configuration for calculating the set current value for each charging device 2 to which the electric vehicle 5 is connected. In this embodiment, the current setting unit 113 calculates a power value by dividing the allowable power value input from the allowable power acquisition unit 111 by the number of connections input from the connection detection unit 112. If the calculated power value exceeds the rated power value of each charging device 2 (for example, 6kW), the current setting unit 113 sets the rated power value to the calculated power value. The current setting unit 113 calculates a current value according to the calculated power value. In this embodiment, since the voltage of the commercial power supply 9 is 200V, the current value is calculated by dividing the power value by 200. The current setting unit 113 sets the calculated current value as the common set current value for each charging device 2 to which the electric vehicle 5 is connected.

[0042] For example, if the allowable power value is 15kW and there are 2 connected units as shown in Figure 1(a), the calculated power value is 7.5kW (=15÷2), so the rated power value is set to 6kW, and the corresponding current value is set to 30A (=6000÷200). Also, if the allowable power value is 15kW and there are 5 connected units, the calculated power value is 3kW (=15÷5), and the corresponding current value is set to 15A (=3000÷200).

[0043] The current setting unit 113 may set the current value to a value smaller than the calculated current value in order to provide a slight margin. The current setting unit 113 transmits the set current value to each charging device 2 to which the electric vehicle 5 is connected via the communication unit 12. The current setting unit 113 does not need to transmit the set current value to charging devices 2 to which the electric vehicle 5 is not connected, or it may transmit the set current value to all charging devices 2 simultaneously. Charging devices 2 to which the electric vehicle 5 is not connected will not perform charging even if they receive the set current value.

[0044] Figure 3 is an example flowchart illustrating the current setting process performed by the control unit 11. This current setting process is for notifying each charging device 2 of the set current value. This current setting process is executed at predetermined intervals.

[0045] First, the allowable power value is acquired (S1). Specifically, the allowable power acquisition unit 111 acquires the allowable power value input from the higher-level device 8. Next, the connection of the electric vehicle 5 is detected (S2). Specifically, the connection detection unit 112 determines whether or not the electric vehicle 5 is connected to the charging device 2 based on the connection detection signal and disconnection detection signal input from each charging device 2. Next, the number of connections is detected (S3). Specifically, the connection detection unit 112 detects the number of connections, which is the number of charging devices 2 to which the electric vehicle 5 is connected. Next, the set current value is calculated (S4). Specifically, the current setting unit 113 calculates a power value by dividing the allowable power value by the number of connections to make it less than or equal to the rated power value, and calculates a corresponding current value as the set current value.

[0046] Next, it is determined whether or not a change in the set current value is necessary (S5). Specifically, the current setting unit 113 determines whether or not the calculated set current value has changed. If a change in the set current value is not necessary (S5: NO), the current setting process is terminated. On the other hand, if a change in the set current value is necessary (S5: YES), the changed set current value is transmitted to the charging device 2 (S6), and the current setting process is terminated. Specifically, the current setting unit 113 transmits the changed set current value to each charging device 2 via the communication unit 12. Note that the process shown in the flowchart of Figure 3 is just one example, and the current setting process performed by the control unit 11 is not limited to what is described above. For example, the set current value may be calculated (S4) and the set current value changed (S6) only when the allowable power value obtained in step S1 or the number of connections detected in step S3 has changed.

[0047] Figure 4 is a time chart illustrating the set current value in response to changes in the number of connections and the allowable power value. Figure 4(a) shows the time change in the allowable power value input from the host device 8. Figure 4(b) shows the time change in the number of connections detected by the connection detection unit 112. Figure 4(c) shows the time change in the set current value set by the current setting unit 113. In Figure 4(c), the power value corresponding to the set current value is indicated in parentheses.

[0048] Time t 11 Before that, the allowable power value has been 15 kW. At time t 11 At this time, when one electric vehicle 5 is connected to any one of the charging devices 2, the number of connections changes from 0 to 1. As a result, the set current value changes from 0 A to 30 A corresponding to the rated power value of 6 kW. After that, at time t 12 At this time, the number of connections changes to 2, but the set current value remains 30 A.

[0049] Time t 13 At this time, when the number of connections changes to 3, the set current value changes to 25 A (= 15 kW ÷ 3 units ÷ 200 V). After that, at time t 14 At this time, when the number of connections changes to 5, the set current value changes to 15 A (= 15 kW ÷ 5 units ÷ 200 V). Also, after that, at time t 15 At this time, when the number of connections changes to 4, the set current value changes to 18.75 A (= 15 kW ÷ 4 units ÷ 200 V).

[0050] Time t 16 At this time, when the allowable power value changes to 10 kW, the set current value changes to 12.5 A (= 10 kW ÷ 4 units ÷ 200 V). After that, at time t 17 At this time, when the number of connections changes to 2, the set current value changes to 25 A (= 10 kW ÷ 2 units ÷ 200 V). Also, after that, at time t 18 At this time, when the number of connections changes to 1, the set current value changes to 30 A corresponding to the rated power value of 6 kW. At any time, the power output by the charging system A1 is below the allowable power value.

[0051] Next, the operation and effects of the charging system A1 according to this embodiment will be described.

[0052] According to this embodiment, the current setting unit 113 of the charging control device 1 receives the allowable power value acquired by the allowable power acquisition unit 111 and the number of connections detected by the connection detection unit 112 as input. The current setting unit 113 calculates a power value by dividing the allowable power value by the number of connections, and if it exceeds the rated power value, it sets it to the rated power value. The current setting unit 113 then sets the current value corresponding to the calculated power value as a common set current value for each charging device 2 to which the electric vehicle 5 is connected. The communication unit 12 then transmits the set current value to the corresponding charging device 2, and each charging device 2 transmits a signal corresponding to the received set current value to the electric vehicle 5. The electric vehicle 5 charges the storage battery 54 based on the set current value. Therefore, the charging system A1 is prevented from using power exceeding the allowable power value, and the concentration of power consumption can be suppressed.

[0053] Furthermore, according to this embodiment, the current setting unit 113 sets a common set current value based on a power value obtained by dividing the allowable power value by the number of connections. Therefore, the charging system A1 can charge the connected electric vehicles 5 equally.

[0054] In this embodiment, the case in which the charging device 2 transmits the set current value to the electric vehicle 5 using a CPLT signal has been described, but it is not limited to this. The charging device 2 may transmit the set current value to the electric vehicle 5 by other means. For example, the charging device 2 may transmit the set current value to the electric vehicle 5 by wireless communication.

[0055] Furthermore, although this embodiment describes the case in which the charging device 2 charges an electric vehicle 5, it is not limited to this. The charging device 2 may also charge a mobile body other than the electric vehicle 5. Other examples of such mobile bodies include, for example, motorcycles (electric motorcycles, electric-assist bicycles), ships, airplanes and other vehicles, or unmanned mobile bodies such as automated guided vehicles and drones.

[0056] [Second Embodiment] Figure 5 is a diagram illustrating the charging system A2 according to the second embodiment. Figure 5(a) is a block diagram showing the internal configuration of the charging control device 1 of the charging system A2. In Figure 5(a), the description of components other than the charging control device 1 is omitted. Figure 5(b) is an example of a flowchart illustrating the current setting process performed by the control unit 11. The flowchart shown in Figure 5(b) is the same as the flowchart shown in Figure 3, but with step S3 changed to step S11. In Figure 5, elements that are the same or similar as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment. The charging system A2 according to this embodiment differs from the charging system A1 according to the first embodiment in its method of setting the set current value.

[0057] As shown in Figure 5(a), the control unit 11 of the charging control device 1 according to the second embodiment further includes a coefficient acquisition unit 114. In this embodiment, a weighting coefficient is set in advance for each charging device 2. The weighting coefficient is set to a larger value for charging devices 2 that should be given priority for charging, for example, a numerical value between 0 and 1, and is stored in advance in a storage unit (not shown). The coefficient acquisition unit 114 is a functional configuration for acquiring the weighting coefficient. The coefficient acquisition unit 114 reads the respective weighting coefficients of the charging devices 2 to which the electric vehicle 5 is connected, as detected by the connection detection unit 112, from the storage unit and outputs them to the current setting unit 113 (step S11 in Figure 5(b)).

[0058] In the second embodiment, the current setting unit 113 distributes the allowable power value according to the weighting coefficients acquired by the coefficient acquisition unit 114 and sets the set current value for each charging device 2 to which the electric vehicle 5 is connected. The current setting unit 113 calculates the sum of the weighting coefficients acquired by the coefficient acquisition unit 114 (hereinafter referred to as the "sum of coefficients"). Then, for each charging device 2, the current setting unit 113 calculates the power value distributed according to the weighting coefficients by dividing the allowable power value by the sum of coefficients and multiplying by the corresponding weighting coefficient. If the distributed power value exceeds the rated power value of the corresponding charging device 2, the current setting unit 113 sets the rated power value as the distributed power value for the charging device 2. The current setting unit 113 calculates a current value corresponding to the distributed power value (for example, by dividing the power value by 200). The current setting unit 113 sets the calculated current value as the set current value for the corresponding charging device 2.

[0059] For example, let's consider a case where an electric vehicle 5 is connected to three charging devices 2a, 2b, and 2c (see Figure 1(a)), each with a permissible power value of 15kW and a weighting coefficient of "0.8" (relatively high priority), and also to two charging devices 2d and 2e, each with a weighting coefficient of "0.3" (relatively low priority). In this case, the sum of the coefficients is "3 (=0.8 × 3 + 0.3 × 0.2)". The power values ​​allocated to charging devices 2a, 2b, and 2c are each "4kW (=15 ÷ 3 × 0.8)", so the corresponding current value is set to 20A (=4000 ÷ 200). The power values ​​allocated to charging devices 2d and 2e are each "1.5kW (=15 ÷ 3 × 0.3)", so the corresponding current value is set to 7.5A (=1500 ÷ 200). Furthermore, the current setting unit 113 may set a value smaller than the calculated current value as the set current value in order to provide a slight margin. As in the first embodiment, when the allowable power value of 15kW is equally distributed to the five charging devices 2, the set current value of each charging device 2 will be 15A (see Figure 4). However, by distributing the allowable power value according to the weighting coefficient, the charging system A2 can set the set current value of the charging devices 2a, 2b, and 2c, which have a relatively higher priority, to 20A, as shown in the example above, and charge them with a larger current with priority over the others.

[0060] According to this embodiment, the current setting unit 113 of the charging control device 1 calculates the sum of each weighting coefficient (sum of coefficients) acquired by the coefficient acquisition unit 114. For each charging device 2, the current setting unit 113 calculates the power value allocated according to the weighting coefficient by dividing the allowable power value by the sum of coefficients and multiplying by the corresponding weighting coefficient, and sets the power value to the rated power value if it exceeds the rated power value. Then, the current setting unit 113 sets the current value corresponding to the calculated power value as the set current value for the corresponding charging device 2. Therefore, the charging system A2 is prevented from using power exceeding the allowable power value, and the concentration of power consumption can be suppressed.

[0061] Furthermore, according to this embodiment, the current setting unit 113 sets the set current value based on the power values ​​allocated according to the weighting coefficient. Therefore, the charging system A2 can preferentially charge the electric vehicle 5 connected to the charging device 2, which has a higher weighting coefficient, with a larger current.

[0062] [Third Embodiment] Figure 6 is a diagram illustrating the charging system A3 according to the third embodiment. Figure 6(a) is a block diagram showing the internal configuration of the charging control device 1 of the charging system A3. In Figure 6(a), the configuration other than the charging control device 1 is omitted. Figure 6(b) is an example of a flowchart illustrating the current setting process performed by the control unit 11. In Figure 6, elements that are the same as or similar to those in the first embodiment are denoted by the same reference numerals as in the first embodiment. The charging system A3 according to this embodiment differs from the charging system A1 according to the first embodiment in that it changes the set current value according to the actual output current of the charging device 2.

[0063] The control unit 51 of the electric vehicle 5 (see Figure 1(b)) reduces the charging current when the battery 54 approaches full charge, in order to extend the battery life in accordance with the charging characteristics of the battery 54. In addition, the control unit 51 reduces the charging current to prevent failure of the battery 54 when the temperature of the battery 54 reaches a predetermined temperature or higher. Therefore, when the battery 54 is approaching full charge or when the temperature of the battery 54 is high, the output current of the charging device 2 becomes smaller than the set current value. The charging system A3 according to this embodiment readjusts the set current value according to the actual output current of the charging device 2.

[0064] As shown in Figure 6(a), the control unit 11 of the charging control device 1 according to the third embodiment further includes a current acquisition unit 115. Each charging device 2 detects its output current and transmits the detected current value to the charging control device 1 via the communication unit 22. The current acquisition unit 115 is configured to acquire the detected current value of each charging device 2. The current acquisition unit 115 acquires the detected current value received by the communication unit 12 from each charging device 2. The method of acquiring the detected current value by the current acquisition unit 115 is not limited. For example, the charging control device 1 may be equipped with a current sensor that detects the output current of each charging device 2, and the current acquisition unit 115 may acquire the detected current value from the current sensor.

[0065] The current setting unit 113 according to the third embodiment calculates a common set current value for each charging device 2 to which the electric vehicle 5 is connected, in the same manner as the current setting unit 113 according to the first embodiment. The current setting unit 113 then compares the calculated set current value with the detected current value for each charging device 2 acquired by the current acquisition unit 115. If there is a charging device 2 whose detected current value is less than the set current value by a predetermined value or more, the current setting unit 113 resets each set current value. The predetermined value is provided to eliminate detection errors and minute fluctuations in the detected current value for determination, and is set to a value that can be determined to be clearly smaller than the set current value. For charging devices 2 whose detected current value is less than the set current value by a predetermined value or more, the current setting unit 113 resets the detected current value as the set current value. In addition, the current setting unit 113 recalculates and resets the set current value for charging devices 2 whose detected current value is greater than the set current value minus a predetermined value (i.e., charging devices 2 that do not fall under the above category, and may be referred to as "non-applicable charging devices" below). For example, the current setting unit 113 subtracts the power value corresponding to the reset set current value from the allowable power value, and calculates a power value by dividing the subtraction result by the number of non-applicable charging devices. If the calculated power value exceeds the rated power value of each charging device 2, the current setting unit 113 sets the rated power value to the calculated power value. The current setting unit 113 calculates a current value corresponding to the calculated power value and sets the calculated current value as the common set current value for the non-applicable charging devices.

[0066] For example, as shown in the example above, if the allowable power value is 15kW and there are 5 connected units, the set current value for each charging device 2 will be set to 15A. However, if, for example, the detected current value of charging device 2a is 5A, the set current value for charging device 2a will be reset to the detected current value of 5A. Also, the set current values ​​for charging devices 2b, 2c, 2d, and 2e will be reset to 17.5A (=(15kW-5A×200V)÷4 units÷200V).

[0067] As shown in the flowchart of Figure 6(b), in the current setting process performed by the control unit 11 according to this embodiment, if the result is "NO" in step S5 of the flowchart in Figure 3, that is, if neither the allowable power value nor the number of connections changes and there is no need to change the set current value, the detected current value is acquired (S21). Specifically, the current acquisition unit 115 acquires the detected current value received by the communication unit 12 from each charging device 2. Next, it is determined whether or not there is a charging device 2 whose detected current value is less than the set current value by a predetermined value or more (S22). If there is no charging device 2 whose detected current value is less than the set current value by a predetermined value or more (S22: NO), the set current value is not changed and the current setting process is terminated. On the other hand, if there is a charging device 2 whose detected current value is less than the set current value by a predetermined value or more (S22: YES), the set current value is reset (S23), the set current value is changed (S6), and the current setting process is terminated. Specifically, the current setting unit 113 resets the detected current value as the set current value for charging devices 2 whose detected current value is less than or equal to a predetermined value, and recalculates and resets the set current value for charging devices that do not fall under this category.

[0068] In this embodiment as well, the same effects as in the first embodiment can be achieved. Furthermore, according to this embodiment, if there is a charging device 2 in which the detected current value is less than or equal to a predetermined value from the set current value, the current setting unit 113 resets each set current value. For charging devices 2 in which the detected current value is less than or equal to a predetermined value from the set current value, the current setting unit 113 resets the detected current value as the set current value, and for charging devices that do not fall under this category, it recalculates and resets the set current value. Therefore, the charging system A3 can appropriately reallocate the current that is not used by the electric vehicle 5 when the control unit 51 of the electric vehicle 5 reduces the charging current below the set current value.

[0069] The charging system according to the present invention is not limited to the embodiments described above. The specific configuration of each part of the charging system according to the present invention can be modified in various ways. [Explanation of symbols]

[0070] A1-A3: Charging system, 1: Charging control device, 11: Allowable power acquisition unit, 112: Connection detection unit, 113: Current setting unit, 114: Coefficient acquisition unit, 115: Current acquisition unit, 12: Communication unit, 2: Charging device, 5: Electric vehicle, 51: Storage battery, 8: Higher-level equipment

Claims

1. Multiple charging devices for charging the battery of an electric mobile body that moves by driving an electric motor with the power of the battery, A charging control device that controls the plurality of charging devices, Equipped with, The charging control device is An allowable power acquisition unit acquires an allowable power value which is the maximum allowable value of the total output power of the plurality of charging devices, A connection detection unit detects the connected charging device to which the electric mobile body is connected among the plurality of charging devices, A current setting unit sets a set current value, which is a current value for setting the output current of each connected charging device, based on the detection result by the connection detection unit and the allowable power value. A communication unit that transmits each of the aforementioned set current values ​​to the corresponding connected charging device, Equipped with, Each of the aforementioned charging devices transmits a signal corresponding to the received set current value to the connected electric vehicle. The charging control device further includes a current acquisition unit that acquires a detected current value obtained by detecting the output current of each charging device. The current setting unit, when the detected current value of each connected charging device is less than or equal to a predetermined value from the corresponding set current value, resets the detected current value as the set current value. For non-applicable charging devices whose detected current value is greater than the value obtained by subtracting the predetermined value from the corresponding set current value, the unit subtracts the power value corresponding to the reset set current value from the allowable power value, divides the subtraction result by the number of non-applicable charging devices, and sets a current value corresponding to the power value obtained as the common set current value for the non-applicable charging devices. Charging system.

2. The current setting unit sets each of the set current values ​​to a current value that is less than or equal to the power value obtained by dividing the allowable power value by the number of connected charging devices detected by the connection detection unit. The charging system according to claim 1.

3. The charging control device further includes a coefficient acquisition unit that acquires a weighting coefficient set for each of the connected charging devices detected by the connection detection unit, The current setting unit sets each of the set current values ​​to a current value that is less than or equal to the power value obtained by allocating the allowable power value according to the weighting coefficient. The charging system according to claim 1.

4. The aforementioned power capacity acquisition unit acquires the aforementioned power capacity value from a higher-level device that performs energy management. The charging system according to claim 1.

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