Charging system and charging planning method

Abstract

Efficiently charges multiple electric vehicles. [Solution] The charging planning unit (100) of the charging system (1) selects one of the charging connectors (50) to which the electric vehicle (V) is connected, which has a connector temperature belonging to a lower temperature range among the pre-defined temperature ranges, as the charging connector for the next charging cycle.

Description

Technical Field

[0001] The present invention relates to a charging system and a charging planning method.

Background Art

[0002] There is known a charging device provided with a charging connector for connecting to an electric vehicle. There is also known a charging device provided with a plurality of charging connectors that performs so-called rotation charging (sequential charging) in which charging is cyclically executed for each electric vehicle connected to each charging connector at predetermined time intervals, so that charging of a plurality of electric vehicles can be performed with a power source of limited capacity.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In performing such sequential charging, it is expected to efficiently execute charging of a plurality of electric vehicles. In view of such problems, one aspect of the present invention aims to realize a charging system that can efficiently execute charging of a plurality of electric vehicles.

Means for Solving the Problems

[0005] To solve the above problems, one aspect of the present invention provides a charging system capable of sequentially charging multiple electric vehicles, comprising: multiple charging connectors for connecting to the electric vehicles; a power supply unit for supplying power for charging; a switching unit for switching which of the charging connectors the power supply unit is connected to; a control unit for controlling the power supply unit and the switching unit; and a charging planning unit for determining which of the charging connectors to use for charging, wherein each charging connector has a temperature sensor for detecting the connector temperature, which is the temperature of the respective charging connector, and the charging planning unit acquires the temperature of each connector and, from among the charging connectors to which the electric vehicles are connected, determines the charging connector that shows a connector temperature belonging to a lower temperature band among a plurality of pre-divided temperature bands as the charging connector for the next charging.

[0006] To solve the above problems, another aspect of the present invention provides a charging planning method for sequentially charging a plurality of electric vehicles, comprising: a charging system having a plurality of charging connectors for connecting to electric vehicles, the method comprising: obtaining the connector temperature, which is the temperature of the charging connector, for each of the charging connectors; and determining, from among the charging connectors to which the electric vehicles are connected, the charging connector that exhibits a connector temperature belonging to a lower temperature band among a plurality of predetermined temperature bands, as the charging connector for the next charge.

[0007] The charging planning unit of the charging system according to the above embodiment of the present invention may be implemented by a computer. In this case, a control program for a charging device that implements the control unit by a computer by operating the computer as each part (software element) of the control unit, and a computer-readable recording medium on which the program is recorded, also fall within the scope of the present invention. [Effects of the Invention]

[0008] According to one aspect of the present invention, a charging system capable of efficiently charging multiple electric vehicles can be realized. [Brief explanation of the drawing]

[0009] [Figure 1] This is a diagram showing an overview of a charging system according to an embodiment of the present invention. [Figure 2] This is a schematic diagram showing a charging connector for a charging system according to an embodiment of the present invention. [Figure 3] This table shows an example illustrating the charging plan determined by the charging planning unit of the charging system according to an embodiment of the present invention. [Figure 4] This flowchart shows an example of operation of a charging system according to an embodiment of the present invention. [Modes for carrying out the invention]

[0010] [Embodiment] Embodiments of the present disclosure will be described in detail below with reference to Figures 1 to 4. In the embodiments for carrying out the invention, the function of the charging system to charge a secondary battery (storage battery) mounted on an electric vehicle (EV) will be mainly described, but the charging system may also be a charge / discharge device that has the function of discharging power stored in the secondary battery. If the charging system has a discharge function, the power discharged may be connected to the grid and flowed back in, or it may be supplied to a load.

[0011] <Overview of the charging system> Figure 1 is a diagram showing an overview of a charging system 1 according to an embodiment of the present disclosure. The charging system 1 is a system that can charge electric vehicles V (V1, V2, V3, V4…) through charging connectors 50 (501, 502, 503, 504…).

[0012] The charging system 1 can supply charging power to the secondary batteries of each electric vehicle V1, V2, V3, V4… through any of the charging connectors 50, but only to one electric vehicle V at a time. The charging system 1 includes a charging planning unit 100, a control unit 10, a power supply unit 20, a switching unit 30, a plurality of stands 40, and a plurality of charging connectors 50 (501, 502, 503, 504…).

[0013] The power supply unit 20 is a power source that receives power from the commercial grid and supplies charging power to the secondary battery of the electric vehicle V. The switching unit 30 is a circuit that switches the connections so that when charging, only one of the multiple charging connectors 50 (501, 502, 503, 504…) provided by the charging system 1 is connected to the power supply unit 20. For this reason, the switching unit 30 has a switch 31 for each charging connector 50 that switches between connecting and disconnecting the charging connector 50 to the power supply unit 20.

[0014] In other words, each switch 31 is provided for each power line 61 connected to each charging connector 50. The switching unit 30 opens and closes each switch 31 according to the instructions of the control unit 10. Specifically, each switch 31 may be an electromagnetic relay or a semiconductor switch whose opening and closing is controlled by the control unit 10. "Rotating charging," in which multiple electric vehicles V are charged in sequence and alternately, is a concept included in "sequential charging."

[0015] Furthermore, the switching unit 30 may be configured to synchronously switch not only the power lines (power lines 61) that supply charging power, but also at least a portion of the signal line group 62 (not shown in Figure 1), which is a communication line between the charging connector 50 and the control unit 10. In Figure 1, only the power lines 61, which are the circuit for charging power supplied from the power supply unit 20, are shown. The switching unit 30 and the stand 40, and the stand 40 and the charging connector 50 are connected by cables 60. As will be described later, the cables 60 house the power lines 61 and the signal line group 62 mentioned above.

[0016] The stand 40 is a structure physically connected to the charging connector 50 via the cable 60 and capable of storing the unused charging connector 50. The stand is installed near the parking space of each electric vehicle V to be charged. The stand

[0017] is a terminal device for connecting to the electric vehicle V during charging, also referred to as a charging station or the like. As shown in the example represented in FIG. 1, the stand may be provided for each charging connector 50 (501, 502, 503, 504...), or the stand may be provided for a plurality of, for example, two charging connectors 50.

[0017] The stand

[0018] may be appropriately provided with a display unit such as a lamp and a button or the like for switching the availability of charging using the charging connector 50 connected to the stand . The form of the stand may be a so-called free-standing stand erected on the vehicle running surface. However, when there is a building wall near the parking space, a wall-mounted structure may be used instead of the stand .

[0018] <Charging connector, cable> The charging connector 50 is a component that is connected to the vehicle-side connector provided in the electric vehicle V and enables the supply of charging power from the charging system 1 to the electric vehicle V side. FIG. 2 is a schematic diagram for explaining the function and structure of the charging connector 50. In FIG. 2, in the side view G21, the outer shape and the main part of the charging connector 50 are superimposed and shown. In the front view G22, the front of the connection part 55 with the vehicle-side connector is schematically shown.

[0019] The connection part 55 of the charging connector 50 has a pair of charging terminals 51 and one or more signal connectors 52. Each signal connector 52 has a plurality of signal connection terminals. In the charging connector 50, a temperature sensor 53 for detecting the temperature of the charging connector 50 (hereinafter, connector temperature) is provided near the charging terminal 51. The temperature sensor 53 preferably detects the temperature of the charging terminal 51 as the temperature of the charging connector 50 (connector temperature).

[0020] As shown in Fig. 2, the cable 60 connecting the charging connector 50 and the switching unit 30 consists of a power line 61 and a signal line group 62. In Fig. 1, the display of such a signal line group 62 is omitted. The power line 61 is a line for transmitting charging power to the electric vehicle V and is connected to a pair of charging terminals 51. The signal line group 62 transmits various signals. Each signal line connected to the signal connector 52 is included in the signal line group 62. The signal line group 62 also includes a signal line for transmitting the output signal of the temperature sensor 53.

[0021] <Control unit, charging plan unit> The control unit 10 is a functional block that controls each part of the charging system 1 such as the power supply unit 20, the switching unit 30, the stand 40, and the charging connector 50 to execute charging, and also exchanges information related to charging with the connected electric vehicle V.

[0022] The charging plan unit 100 is a functional block including a connector temperature acquisition unit 101, an EV information acquisition unit 102, and a calculation unit 103. The connector temperature acquisition unit 101 is a functional block that acquires the connector temperature of each charging connector 50. The EV information acquisition unit 102 is a functional block that acquires information regarding the required amount of power, which is the amount of power required for charging, from the electric vehicle V connected to the charging connector 50.

[0023] Based on the information acquired by the connector temperature acquisition unit 101 and the EV information acquisition unit 102, the calculation unit 103 is a functional block that formulates a charging plan, including determining which of the plurality of charging connectors 50 to use to execute at least the next charging in sequence during charging.

[0024] As is well known for a system capable of executing information processing, each of the hardware of the control unit 10 and the charging plan unit 100 may be physically concentrated in one device, or may be distributed, and in some cases, a part of its function may be configured on the cloud.

[0025] In a typical example, the control unit 10 may be housed together with the power supply unit 20 in a single enclosure and configured as a device such as an EV charger, and the functions of the charging planning unit 100 may be provided as part of the functions of a server, which is a higher-level system for such an EV charger. In this case, the connector temperature acquisition unit 101 and the EV information acquisition unit 102 of the charging planning unit 100 may be configured to acquire the connector temperature of the charging connector 50 or information from the electric vehicle V via the control unit 10 of such an EV charger.

[0026] Furthermore, the server in this case may be an information processing system that manages multiple charging systems 1 and multiple electric vehicles V, for example, used by a bus operator or a taxi operator.

[0027] When the charging system 1 performs sequential charging, the control unit 10 performs one charge in sequential charging as follows: The duration of one charge in sequential charging for a particular electric vehicle V is predetermined as the first time T1. The control unit 10 attempts to charge at the maximum current value Imax determined for the charging system 1 in order to improve the time efficiency of charging for multiple electric vehicles V.

[0028] The control unit 10 monitors the connector temperature of the charging connector 50 used for charging, and when the connector temperature reaches a predetermined upper limit temperature Tmax, it switches to charging at a limit current value lower than the maximum current value Imax. For example, if the maximum current value Imax is 200A, the limit current value is set to approximately 125A.

[0029] In both cases—charging at the maximum current value Imax and charging at the limited current value—if the current exceeds the upper limit value specified by the electric vehicle V, charging will be performed at that upper limit value. Generally, as the secondary battery of the electric vehicle V approaches full charge, the upper limit value specified by the electric vehicle V becomes more restricted.

[0030] Furthermore, in cases where sequential charging is not performed, that is, when the charging system 1 uses a single charging connector 50 to charge only one electric vehicle V, the charging duration for the electric vehicle V is predetermined as the second time T2. The second time T2 is, for example, 255 minutes.

[0031] <Formulation of charging plans by the Charging Planning Department> Next, we will explain the method by which the charging planning unit 100 formulates a charging plan when the charging system 1 performs sequential charging, referring to a specific example shown in Figure 3. Figure 3 is a table summarizing the information on each of the charging connectors 501 to 504 that the charging planning unit 100 uses or calculates for the charging plan.

[0032] In the example shown in Figure 3, electric vehicles V1 to V3, which have not yet been fully charged, are connected to charging connectors 501 to 503, respectively, while electric vehicle V4, which has not yet been fully charged, is not connected to charging connector 504. In other words, electric vehicle V4 is not physically connected to charging connector 504, or the secondary battery of electric vehicle V4 using charging connector 504 has been fully charged.

[0033] When charging the secondary battery of the electric vehicle V4 using the charging connector 504 is complete, the operator may be able to remove the charging connector 504 from the electric vehicle V4, and in this case, the connector lock may be released.

[0034] The connector temperature acquisition unit 101 acquires the connector temperature detected by the temperature sensor 53 of each charging connector 50. Note that the connector temperature acquisition unit 101 may omit acquiring the connector temperature of charging connectors 50 to which the electric vehicle V is not connected. In the example shown in Figure 3, the connector temperatures acquired by the connector temperature acquisition unit 101 for charging connectors 501 to 504 were 36°C, 80°C, 40°C, and 33°C, respectively.

[0035] Furthermore, the EV information acquisition unit 102 acquires information from the electric vehicle V connected to the charging connector 50 regarding the required amount of power, which is the amount of power required for charging requested by the electric vehicle V. Here, the required amount of power is the amount of power required until the secondary battery of the electric vehicle V is fully charged.

[0036] This required power is the value obtained by subtracting the current charge amount (charged power) from the battery capacity of the secondary battery equipped in the electric vehicle V. Here, the battery capacity of the secondary battery may be the rechargeable capacity of the secondary battery specified for each electric vehicle V. The charge amount may be calculated by multiplying the battery capacity of the secondary battery by the SOC (State of Charge). Therefore, the information regarding the required power may be the required power itself, the battery capacity of the secondary battery and the current charge amount, or the battery capacity of the secondary battery and the SOC.

[0037] In the example shown in Figure 3, the electric vehicle V can provide information regarding the required amount of power, including the battery capacity and SOC of the secondary battery, and the EV information acquisition unit 102 acquires the battery capacity and SOC of the secondary battery. For electric vehicles V1 to V3 connected to charging connectors 501 to 503, the SOC and battery capacity of the secondary battery acquired by the EV information acquisition unit 102 were 30%, 50kWh, 50%, 100kWh, 40%, and 50kWh, respectively.

[0038] Next, the calculation unit 103 calculates the required power for each electric vehicle V connected to each charging connector 50 based on the information regarding the required power. This step is unnecessary if the EV information acquisition unit 102 acquires the required power itself as information regarding the required power. In the example shown in Figure 3, the calculation unit 103 calculated the required power for electric vehicles V1 to V3 connected to charging connectors 501 to 503 to be 35kWh, 50kWh, and 30kWh, respectively.

[0039] Furthermore, the calculation unit 103 determines which of the predetermined temperature zones the connector temperature of each charging connector 50 belongs to. Examples of temperature zone classifications are as follows: Band A: Below 50℃ Band B: Over 50°C and below 60°C Bandwidth C: Over 60°C and below 70°C Bandwidth D: Over 70°C and below 80°C Bandwidth E: Over 80°C and below 90°C Bandwidth F exceeds 90℃.

[0040] The upper limit temperature of 50°C in band A, which is the lowest temperature band among the temperature bands thus divided to distribute the connector temperature, is defined as follows: It is set from the connector temperature at the start of charging (e.g., 50°C) such that the connector temperature does not reach the upper limit temperature Tmax (e.g., 90°C) when a single charge is performed with a maximum current value Imax for a charging duration of the first hour T1 (e.g., 15 minutes). Note that a temperature such as 50°C, which has this significance, is not necessarily limited to being set as the upper limit temperature of the lowest temperature band (band A), but may be set as the upper limit temperature of any temperature band among the divided temperature bands.

[0041] In other words, the upper limit temperature of a particular temperature range among these divided temperature ranges is set from the connector temperature at the start of charging, such that when a single charge with a charging duration of the first time T1 is performed with the maximum current value Imax, the connector temperature does not reach a temperature at which it cannot maintain the maximum current value Imax.

[0042] Furthermore, among these temperature bands that distribute the connector temperature, the lower limit temperature of band F, which is the highest temperature band, above 90°C is defined as the upper limit temperature Tmax. Bands B to E may be defined to appropriately divide the temperature range between 50°C and 90°C.

[0043] The calculation unit 103 then determines that, in sequential charging, charging should be prioritized for the charging connectors 50 to which the electric vehicle V is connected, specifically those connectors that show a lower temperature range. If there are multiple charging connectors that show a temperature range that is the same, the unit further prioritizes those connectors that have a higher power requirement for the secondary battery of the connected electric vehicle V.

[0044] In the example shown in Figure 3, the calculation unit 103 determines that the connector temperatures of charging connectors 501 and 503 belong to band A, and the connector temperature of charging connector 502 belongs to band D. Therefore, it determines that charging connectors 501 and 503 should be given priority over charging connector 502. In other words, charging connector 502 is given priority 3.

[0045] The calculation unit 103 prioritizes the charging connectors 50, as there are multiple connectors 50 that indicate a connector temperature belonging to band A. The calculation unit 103 prioritizes those with a large power requirement for the secondary battery of the connected electric vehicle V, assigning the highest priority (priority 1) to charging connector 501 and the next highest priority (priority 2) to charging connector 503. In this way, the calculation unit 103 determines the priority (order) of charging connectors 501 when charging is performed in sequential charging and formulates a charging plan.

[0046] The calculation unit 103 transmits the determined charging plan to the control unit 10 and has it perform sequential charging according to the charging plan. The charging system 1 may also sequentially charge multiple electric vehicles V according to a charging plan formulated at a certain time in which the prioritization of multiple charging connectors 50 has been set.

[0047] However, it is preferable that the charging system 1 is configured to update the charging plan after each charge in sequential charging and to perform sequential charging based on the latest status. In this case, the charging plan only needs to determine which charging connector 50 is connected to the electric vehicle V that should be charged next, that is, to determine the charging connector 50 with priority 1.

[0048] In other words, the charging planning unit 100 only needs to select one charging connector 50 from among the charging connectors 50 to which the electric vehicle V is connected, that has a connector temperature belonging to a lower temperature range among the pre-defined temperature ranges, and designate that as the charging connector 50 for the next charging cycle.

[0049] Furthermore, if there are multiple charging connectors 50 to which the electric vehicle V is connected that exhibit connector temperatures belonging to a lower temperature range, the charging planning unit 100 can determine from among these multiple charging connectors 50 the charging connector 50 to which the electric vehicle V with the greatest required power is connected as the charging connector 50 for the next charging operation.

[0050] Thus, according to this embodiment, the charging planning unit 100 formulates a charging plan based on the connector temperature of the charging connector 50. Therefore, the charging system 1 can perform time-efficient sequential charging by utilizing high-current charging that causes the connector temperature to rise during charging. In other words, the charging plan by the charging planning unit 100 is designed so that charging at the maximum current value Imax can be maintained as much as possible in each sequential charging cycle. Thus, according to this embodiment, a charging system that can efficiently charge multiple electric vehicles can be realized.

[0051] <Operation of the charging system> The following shows an example of the operation of the charging system 1 using the charging plan formulated by the charging planning unit 100. Here, an example is shown in which the charging plan is updated after each charge in sequential charging. In the following explanation, electric vehicles V connected to the charging connector 50 are excluded from the definition of electric vehicles V that have already completed charging, even though the charging connector 50 remains physically connected.

[0052] Similarly, the term "charging connector 50 to which an electric vehicle V is connected" excludes charging connectors 50 that have already completed charging but remain connected to the electric vehicle V. In this case, when the operator disconnects the charging connector 50 from the electric vehicle V that has completed charging, and another electric vehicle V is connected to the charging connector 50, the charging connector 50 returns to being a "charging connector 50 to which an electric vehicle V is connected."

[0053] Figure 4 is a flowchart showing an example of the operation of the charging system 1. At the start of the flow, it is assumed that there are no electric vehicles V connected to any of the charging connectors 50 in the charging system 1.

[0054] Step S1: The control unit 10 determines whether an electric vehicle V has been connected to any of the charging connectors 50. If an electric vehicle V has been connected, the flow proceeds to step S2. Otherwise, step S1 is repeated.

[0055] Step S2: The control unit 10 starts charging the electric vehicle V using the charging connector 50 to which the electric vehicle V is connected. At this time, since there is only one electric vehicle V connected to the charging connector 50, the control unit 10 will attempt to charge the vehicle for a duration of the second time T2 (for example, 255 minutes). Next, the flow proceeds to step S3.

[0056] Step S3: The control unit 10 determines whether charging of the electric vehicle V is complete. If charging of the electric vehicle V is complete, the flow proceeds to step S16. In this case, the charging (standalone charging) set to a charging duration of the second time T2 is completed before the second time T2 has elapsed, and charging is stopped in step S16. Otherwise, the flow proceeds to step S4.

[0057] Step S4: The control unit 10 determines whether the charging duration has reached the second time T2. If the charging duration has reached the second time T2, the flow proceeds to step S5. In this case, the charging (single charge) that was set to have a charging duration of the second time T2 is temporarily stopped in step S5. Otherwise, the flow proceeds to step S6.

[0058] Step S5: The control unit 10 terminates charging the electric vehicle via the charging connector 50 that is currently charging it. The flow then proceeds to step S2.

[0059] Step S6: The control unit 10 determines whether the electric vehicle V has been connected to any charging connector 50 other than the charging connector 50 currently being used for charging. If it determines that the vehicle has been connected, the process proceeds to step S7. Otherwise, the process returns to step S3. In the latter case, standalone charging continues.

[0060] Step S7: The control unit 10 determines whether the charging duration has exceeded the first time T1 (e.g., 15 minutes). If it has, the flow proceeds to step S8. Otherwise, the flow proceeds to step S11. In the latter case, because another electric vehicle V was connected, the charging that started as a single charge is switched to a single charge in sequential charging from then on.

[0061] Step S8: The charging planning unit 100 formulates a charging plan for the charging connector 50 to which the electric vehicle V is connected. That is, it determines which charging connector 50 will be used for the next charge in sequential charging. The flow then proceeds to step S9.

[0062] Step S9: The control unit 10 terminates charging the electric vehicle via the charging connector 50 that is currently charging it. The flow then proceeds to step S10.

[0063] Step S10: The control unit 10 starts charging the electric vehicle V connected to the charging connector 50 using the charging connector 50 for the next charge determined by the charging planning unit 100. In other words, the control unit 10 starts one charge in the sequential charging process. The flow then proceeds to step S11.

[0064] Step S11: The control unit 10 determines whether charging of the electric vehicle V is complete. If charging of the electric vehicle V is complete, the flow proceeds to step S14. Otherwise, the flow proceeds to step S12.

[0065] Step S12: The control unit 10 determines whether the charging duration has reached the first time T1. If the first time T1 has been reached, the flow proceeds to step S13. Otherwise, the flow returns to step S11.

[0066] Step S13: The control unit 10 determines whether there is another charging connector 50 to which an electric vehicle V is connected, other than the charging connector 50 currently being used for sequential charging. If it determines that there is another, the flow proceeds to step S8. Otherwise, the flow proceeds to step S5. In the latter case, since there is only one electric vehicle connected to the charging system 1, charging is stopped once, and then charging (single-vehicle charging) with a charging duration of the second time T2 is started.

[0067] Step S14: The control unit 10 determines whether there is another charging connector 50 to which an electric vehicle V is connected, other than the charging connector 50 currently being charged. If it determines that there is, the flow proceeds to step S15. Otherwise, the flow proceeds to step S16. In the latter case, since there are no more electric vehicles V to be charged by sequential charging, the flow ends after the charging completion process in step S16.

[0068] Step S15: The flow reaches this step when charging of the charging vehicle V is complete (YES in S11) and there is another charging connector 50 to which the electric vehicle V is connected, in addition to the charging connector 50 to which the current charging is being performed (YES in S14).

[0069] The control unit 10 determines whether there are multiple charging connectors 50 to which electric vehicles V are connected, other than the charging connector 50 currently being charged. If it determines that there are multiple connectors, the flow proceeds to step S8. Otherwise, the flow proceeds to step S5. In the former case, charging will continue sequentially. In the latter case, there is only one electric vehicle V to be charged connected to the charging system 1, and charging (single-vehicle charging) with a charging duration of the second hour T2 will be performed on that electric vehicle V.

[0070] Step S16: The control unit 10 terminates charging the electric vehicle via the charging connector 50. The flow then ends.

[0071] Such a charging system 1 is extremely useful, for example, in situations where it is necessary to complete the charging of a large number of electric vehicles at a bus operator's vehicle depot during off-hours, such as at night. With the charging system 1 according to this embodiment, multiple electric vehicles V can be efficiently charged by connecting a large number of charging connectors 50 to each electric vehicle V and performing the charging operation sequentially.

[0072] Therefore, for example, charging of each electric vehicle V can be completed before the start of operation. Thus, by using the charging system 1 according to this embodiment, the number of charging facilities that need to be installed can be reduced, making it possible to significantly reduce equipment costs in bus operations and the like.

[0073] [Variation] In the operation of the charging system 1 of the above embodiment, in each sequential charging cycle, unless charging of the electric vehicle V is completed midway through, the charging cycle continues until the charging duration reaches the first time T1 (loop of steps S11 and S12).

[0074] However, if a new electric vehicle V is connected to any of the charging connectors 50 while sequential charging is in progress, the charging planning unit 100 may be configured to reset the charging connector 50 for the next charge at that point. In this case, the charging planning unit 100 includes the charging connector 50 to which the new electric vehicle V is connected as a candidate when selecting the next charging connector 50. Alternatively, the current charge may be terminated at that point.

[0075] In other words, when sequential charging is being performed in the charging system 1, if an electric vehicle V is newly connected to one of the charging connectors, the charging planning unit 100 determines the next charging connector 50 to be used, including the charging connector 50 to which the electric vehicle V is connected. The control unit 10 then terminates the current charging cycle in the sequential charging and starts charging using the newly determined charging connector 50. In this modified example, step S12 in the above embodiment is modified as follows.

[0076] Step S12: The control unit 10 determines whether the charging duration has reached the first time T1, or whether a new electric vehicle V has been connected to any of the charging connectors 50 that are not currently charging. If the charging duration has reached the first time T1, or if a new electric vehicle V has been connected, the flow proceeds to step S13. Otherwise, the flow returns to step S11.

[0077] [Examples of implementation using software] The functions of the control unit 10 or the charging planning unit 100 (hereinafter referred to as "device") can be realized by a program that causes the device to function as a computer. In this case, the device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., memory) as hardware for executing the program. By executing the program using this control device and storage device, the functions described in each of the embodiments above are realized.

[0078] The above program may be recorded on one or more computer-readable recording media, not temporary ones. These recording media may or may not be provided by the device. In the latter case, the program may be supplied to the device via any wired or wireless transmission medium. Furthermore, some or all of the functions of each of the above control blocks can also be implemented by logic circuits. For example, an integrated circuit in which logic circuits functioning as each of the above control blocks are formed is also within the scope of the present invention.

[0079] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in the embodiments, etc., are also included within the technical scope of the present invention. [Explanation of Symbols]

[0080] 1 Charging System 10 Control Unit 20 Power supply section 30 Switching section 40 Stands 50 (501, 502, 503, 504) Charging connector 53 Temperature Sensor 60 Cables 61 Power lines 62 signal line group 100 Charging Planning Department 101 Connector temperature acquisition unit 102 EV information acquisition section 103 Calculation Department

Claims

1. A charging system capable of sequentially charging multiple electric vehicles, Multiple charging connectors for connecting to the aforementioned electric vehicle, A power supply unit for supplying power for charging, A switching unit that switches which of the aforementioned charging connectors the power supply unit is connected to, A control unit that controls the power supply unit and the switching unit, The system includes a charging planning unit that determines which charging connector to use to perform the charging, Each of the aforementioned charging connectors has a temperature sensor that detects the connector temperature, which is the temperature of the respective charging connector. The aforementioned charging planning unit, A charging system that acquires the temperature of each of the aforementioned connectors, and from among the charging connectors to which the electric vehicle is connected, determines the charging connector that exhibits a connector temperature belonging to a lower temperature band among a plurality of predetermined temperature bands as the charging connector for the next charging.

2. The aforementioned charging planning unit, From the electric vehicle connected to the charging connector, information regarding the required amount of power, which is the amount of power required for charging requested by the electric vehicle, is obtained. The charging system according to claim 1, wherein if there are multiple charging connectors to which the electric vehicle is connected that exhibit a connector temperature belonging to a lower temperature range, the charging connector to which the electric vehicle with the largest required power is connected is selected from among the multiple charging connectors to be used for the next charging.

3. The charging duration for each charge in the aforementioned sequential charging is set to be the first hour. The charging system according to claim 1 or 2, wherein the upper limit temperature of at least one of the predetermined temperature bands is set from the connector temperature at the start of charging such that the connector temperature does not reach a temperature at which the maximum current value cannot be maintained when a single charge with a charging duration of the first hour is performed at the maximum current value.

4. If the electric vehicle is newly connected to one of the charging connectors, The charging planning unit, including the charging connector in question, then determines which charging connector to use for the next charge. The charging system according to claim 1, wherein the control unit terminates the current charging cycle in the sequential charging and then starts charging again using the charging connector which has been determined.

5. A charging system having multiple charging connectors for connecting to electric vehicles, a charging planning method for sequentially charging multiple said electric vehicles, The steps include obtaining the connector temperature, which is the temperature of the charging connector, for each of the charging connectors, A charging planning method comprising the step of determining, from among the charging connectors to which the electric vehicle is connected, the charging connector that exhibits a connector temperature belonging to a lower temperature band among a plurality of predetermined temperature bands, as the charging connector for the next charging.

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