Charging management device and charging management method

Abstract

To properly execute vehicle charging.SOLUTION: A charging management device includes a schedule generation unit configured to refer to a high-price period in which the average value of a reference electricity price is higher than that of other periods, and to generate a power transition schedule that decreases the output power of a charger after the start of the high-price period relative to the output power of the charger before the start of the high-price period, and increases the output power of the charger after the end of the high-price period relative to the output power of the charger before the end of the high-price period, and a charging control unit configured to control the output power of the charger on the basis of the power transition schedule.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a charge management device and a charge management method for managing charging of a vehicle battery. [Background technology]

[0002] The trading price of electricity, which fluctuates depending on the state of supply and demand for electricity, is called the market price. For example, Patent Document 1 discloses a technology that determines the operation timing of specified equipment installed in a specified area based on the peak time for total power consumption in the area and the market price. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-191076 Summary of the Invention [Problem to be solved by the invention]

[0004] Vehicles such as electric vehicles that have an electric motor as a drive source may charge their onboard batteries at charging stations. However, if the onboard battery is charged unplanned, a lot of electricity may be consumed at times when the market price of electricity is high, which may result in increased charging costs.

[0005] An object of the present invention is to provide a charge management device and a charge management method that are capable of appropriately charging a vehicle. [Means for solving the problem]

[0006] In order to solve the above problem, the charging management device of the present invention includes a schedule generation unit that references a high price period in which the average value of the reference price of electricity is higher than other periods, and generates a power transition schedule that reduces the output power of the charger after the start of the high price period below the output power of the charger before the start of the high price period, and increases the output power of the charger after the end of the high price period above the output power of the charger before the end of the high price period, and a charging control unit that controls the output power of the charger based on the power transition schedule. A charger group may be formed from a plurality of the chargers, and the charging control unit may control the output power of the chargers so that the total output power, which is the sum of the output power of the chargers that make up the charger group, is equal to or less than a predetermined value. The charging control unit may control the output power of the chargers so that the output power of each of the chargers constituting the charger group becomes a value obtained by dividing the predetermined value proportionately in proportion to the rated output power of each of the chargers being charged. When the total output power is equal to or less than the predetermined value, the charging control unit may set the output power to the chargers in the order in which charging becomes possible, and when the total output power exceeds the predetermined value, may not set the output power to the chargers even if charging becomes possible. In order to solve the above problem, the charging management method of the present invention has a computer that references a high price period in which the average value of the reference price of electricity is higher than other periods, generates a power transition schedule that reduces the output power of the charger after the start of the high price period below the output power of the charger before the start of the high price period, and increases the output power of the charger after the end of the high price period above the output power of the charger before the end of the high price period, and based on the power transition schedule, reduces the output power of the charger at the start of the high price period and increases the output power of the charger at the end of the high price period. [Effects of the Invention]

[0007] According to the present invention, it is possible to appropriately charge a vehicle. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram for explaining an outline of the charging system. [Figure 2] FIG. 2 is a block diagram for explaining an outline of the charge management server. [Figure 3] FIG. 3 is a timing chart for explaining fluctuations in market prices. [Figure 4] FIG. 4 is a timing chart for explaining a power transition schedule of the output power of the charging station. [Figure 5] FIG. 5 is a timing chart for explaining the difference in procurement price depending on the charging schedule. [Figure 6] FIG. 6 is a flowchart for explaining the equal division control. [Figure 7] FIG. 7 is a flowchart for explaining the first-come-first-served control. [Figure 8] FIG. 8 is an explanatory diagram showing an example in which the charge control unit controls the start of charging based on a number. [Figure 9] FIG. 9 is an explanatory diagram showing another example in which the charge control unit controls the start of charging based on a number. [Figure 10] FIG. 10 is a block diagram illustrating another example of a charging system. DETAILED DESCRIPTION OF THE INVENTION

[0009] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Dimensions, materials, and other specific values ​​shown in the embodiments are merely examples for facilitating understanding of the invention and, unless otherwise specified, do not limit the present invention. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown.

[0010] (Charging System 1) 1 is a block diagram for explaining an outline of a charging system 1. The charging system 1 includes a vehicle 10, a power supply facility 100, and a charging management server 200.

[0011] Vehicle 10 is an electric vehicle (EV) that runs by driving an electric motor using electricity stored in a battery, and includes battery-powered electric vehicles (BEVs), plug-in hybrid vehicles (PHVs), and the like. Here, examples of uses of vehicle 10 include taxis and hire cars that operate as general passenger vehicle transport businesses. Note that vehicle 10 may also be a private car (ride share), a motorcycle (bike taxi), or the like.

[0012] The power supply facility 100 is a facility capable of supplying power to the vehicle 10. The power supply facility 100 includes a transformer 110, a power meter 120, and a charging stand .

[0013] The transformer 110 receives power supplied via the power transmission and distribution network and converts it into single-phase AC 200V power used at the charging station 130 .

[0014] The power meter 120 is disposed between the transformer 110 and the charging stand 130 and measures the instantaneous current measurement value (A) and voltage (V) supplied to the charging stand 130. The power meter 120 also derives an instantaneous power measurement value (kW) by multiplying the current on the voltage line, the line voltage between the voltage line and the neutral line, and a power factor based on the phase difference between the current and voltage. The power meter 120 also integrates the instantaneous power measurement value (kW) to derive an integrated power energy measurement value (kWh).

[0015] In this embodiment, the power meter 120 is a smart meter equipped with a communication function. Therefore, the power meter 120 can establish communication with, for example, the charge management server 200 via the network 12 and transmit information such as an instantaneous power measurement value (kW) and an integrated power measurement value (kWh).

[0016] A plurality of charging stations (chargers) 130 are installed in a predetermined area accessible to the vehicle 10, and each can output a rated (maximum) power of 6 kW (200 V, 3 A). Such charging stations 130 correspond to standard chargers. The power meter 120 collectively measures the output power of the plurality of charging stations 130. The charging stations 130 also establish communication with, for example, the charging management server 200 via the network 12. The charging stations 130 can change their output power within a range of 0 to 6 kW according to output instructions from the charging management server 200. Here, a 6 kW charger, which corresponds to a standard charger, is illustrated as an example of the output power of the charging station 130; however, this is not a limitation, and chargers with any output power equivalent to a standard charger or a rapid charger can also be applied. Note that, herein, charging stations 130 with a rated output power of 0.6 kW or more but less than 20 kW may be referred to as standard chargers, and charging stations 130 with a rated output power of 20 kW or more may be referred to as rapid chargers.

[0017] The driver connects a charging connector, which is an end of an on-board charging cable connected to the charging stand 130, to a charging port of the vehicle 10. In this way, charging of the battery of the vehicle 10 begins. Note that hereinafter, charging of the battery may also be simply referred to as "charging." Therefore, expressions such as "charging the vehicle 10" refer to charging of the battery of the vehicle 10.

[0018] The charging management server 200 remotely controls the entire power supply facility 100 and manages charging of the vehicle 10. Specifically, when the vehicle 10 requests charging, the charging management server 200 controls the output power of the charging stand 130 connected to the vehicle 10. Furthermore, the charging management server 200 acquires an instantaneous power measurement value (kW) and an integrated power measurement value (kWh) via the power meter 120, and performs charging management so that the power supplied to the charging stand 130 is an appropriate value.

[0019] For example, after closing a taxi business, the driver returns to the power supply facility 100 corresponding to the business. Then, the driver connects the vehicle 10 to the charging station 130 and starts charging in preparation for business the next day. However, if the driver charges the vehicle 10 unplanned, a large amount of electricity may be consumed at a time when the market price (base price) of electricity is high. For example, if the driver immediately starts charging the vehicle 10 after closing business, the time when the market price of electricity is high may overlap with the time when the charging of the vehicle 10 starts, and the procurement price, which is the price at which wholesale electricity is procured from the electricity market, becomes unnecessarily high. As a result, charging costs increase. For ease of explanation, hereinafter, the market price of electricity will be simply referred to as the market price, and the procurement price of wholesale electricity will be simply referred to as the procurement price.

[0020] Therefore, the charging management server 200 reduces the charging cost by suppressing charging at a time when the market price is high in response to fluctuations in the market price.

[0021] (Charging schedule management) FIG. 2 is a block diagram for explaining an outline of the charge management server 200. The charge management server 200 is configured with one or more information processing devices and is capable of performing distributed processing or parallel processing. When the charge management server 200 is configured with multiple information processing devices, the multiple information processing devices are connected to each other via a network 12. Each information processing device has a semiconductor integrated circuit including one or more processors, a ROM storing programs and the like, a RAM used as a work area, and the like. The processor of the charge management server 200 runs programs to function as functional units such as a server communication unit 210, an information acquisition unit 212, a period determination unit 214, a schedule generation unit 216, and a charge control unit 218.

[0022] The server communication unit 210 establishes communication with external devices, such as the power meter 120 and the charging stand 130, via the network 12.

[0023] The information acquisition unit 212 acquires various information from external sources. For example, the information acquisition unit 212 acquires an estimated value of the market price (yen / kWh) in 30-minute increments from the Japan Electric Power Exchange (JEPX) through an electricity trading market such as the day-ahead market (spot). Hereinafter, the estimated value of the market price acquired through the electricity trading market will be simply referred to as the market price. In addition, the information acquisition unit 212 acquires information related to electricity, such as an instantaneous power measurement value (kW) and an integrated power measurement value (kWh), from the power meter 120.

[0024] The period determination unit 214 determines a high price period. A high price period is a period in which the average market price is higher than periods other than the high price period within a day.

[0025] FIG. 3 is a timing chart for explaining fluctuations in market prices. The market price is the price at which the supply and demand of electricity are in balance. Generally, when demand is less than supply, the market price falls, and when supply is less than demand, the market price rises. Such market prices are updated, for example, every 30 minutes.

[0026] In the example of Figure 3, the market price fluctuates at 10 yen / kWh from midnight to 3:00, 5 yen / kWh from 3:00 to 9:00, 10 yen / kWh from 9:00 to 15:00, 30 yen / kWh from 15:00 to 18:00, 20 yen / kWh from 18:00 to 21:00, and 10 yen / kWh from 21:00 to 24:00.

[0027] Here, the period determination unit 214 determines a period in which the market price satisfies a predetermined condition as a high price period. The predetermined condition is, for example, a period in which the market price is equal to or greater than a predetermined value (e.g., 15 yen / kWh). In this case, the period determination unit 214 can determine the period from 3:00 PM to 9:00 PM as the high price period, as shown by hatching in FIG. 3. In FIG. 3, the average market price during the high price period (3:00 PM to 9:00 PM) is 25 yen / kWh, and the average market price during periods other than the high price period (midnight to 3:00 PM and 9:00 PM to midnight) is 8.3 yen / kWh. Therefore, the average market price during the high price period is higher than the average market price during periods other than the high price period.

[0028] In this example, the predetermined value is set to 15 yen / kWh. However, the predetermined value is not limited to this and can be determined arbitrarily. Furthermore, the period determination unit 214 may change the predetermined value depending on the season, date, altitude, whether or not an event is taking place, etc., so as to reduce the charging cost.

[0029] The schedule generation unit 216 generates a power transition schedule based on the high price period determined by the period determination unit 214. The power transition schedule indicates a target transition of the output power of the charging stand 130.

[0030] FIG. 4 is a timing chart illustrating a power transition schedule for the output power of the charging stand 130. The schedule generation unit 216 generates a power transition schedule in which the output power of the charging stand 130 after the start of a high price period (during the high price period) is reduced below the output power of the charging stand 130 before the start of the high price period, and the output power of the charging stand 130 after the end of the high price period is increased above the output power of the charging stand 130 before the end of the high price period (during the high price period). To achieve this schedule, in the example of FIG. 4, the output power of the charging stand 130 is targeted to be reduced from 6 kW (3 A) to 1.2 kW (0.6 A) at 3:00 PM and increased from 1.2 kW to 6 kW at 9:00 PM. Therefore, the power transition schedule is 6 kW from midnight to 3:00 PM, 1.2 kW from 3:00 PM to 9:00 PM, and 6 kW from 9:00 PM to midnight.

[0031] Here, the output power during the high price period is set to 1.2 kW instead of 0 for the following reason: If the output power becomes 0 kW, the driver cannot distinguish whether the output power is being limited by the power transition schedule or whether power is not being supplied due to a malfunction of the charging stand 130. Therefore, by setting the output power during the high price period to a value greater than 0 kW, for example 1.2 kW, it is possible to distinguish this from a malfunction of the charging stand 130 and determine that power is being supplied from the charging stand 130.

[0032] The charging control unit 218 remotely controls the output of each charging stand 130 based on the power transition schedule generated by the schedule generation unit 216. For example, when a driver desires to charge the vehicle 10 and connects a charging connector to a charging port of the vehicle 10, the charging control unit 218 determines a charging schedule for the vehicle 10 based on the power transition schedule. The charging schedule indicates the transition of the output power of the charging stand 130 for charging the vehicle 10. Here, the charging control unit 218 determines the charging schedule without referring to the SOC (State Of Charge) of the vehicle 10 at the start of charging, but assuming that the SOC is 0.

[0033] Note that, here, an example in which the charging control unit 218 determines a charging schedule without referring to the SOC will be described. However, this is not limited to such a case. If the SOC can be directly referred to or estimated, the charging control unit 218 may determine a charging schedule by referring to the SOC. For example, if the vehicle 10 is a taxi and the charging station 130 is provided in the power supply facility 100 corresponding to a business establishment, the charging management server 200 can identify the vehicle model of the vehicle 10 to some extent. In this case, the charging control unit 218 can estimate the maximum SOC of the battery from the vehicle model of the vehicle 10. Furthermore, the timing to start charging of such a vehicle 10 is likely to be after business hours. Therefore, the charging control unit 218 can estimate the SOC at the start of charging by simulation or actual measurement. Once the SOC is estimated in this way, the charging control unit 218 refers to the SOC and determines a charging schedule such that charging is performed by the difference obtained by subtracting the SOC at the start of charging from the maximum chargeable SOC.

[0034] Furthermore, if the SOC can be directly referenced or estimated, the charging control unit 218 may control the output of the charging station 130 according to the ratio of the SOCs of the batteries of the vehicles 10. For example, when multiple vehicles 10 are charging at the same time, the charging control unit 218 may set the output power of the charging station 130 for vehicles 10 with a low SOC to be relatively higher than the output power of the charging station 130 for vehicles 10 with a high SOC. This configuration allows the charging completion timings of multiple vehicles 10 to be closer together, making it possible to charge efficiently, for example, around the start of taxi operations the next day. Furthermore, the charging control unit 218 may set the output power of the charging station 130 for vehicles 10 with a high SOC to be relatively higher than the output power of the charging station 130 for vehicles 10 with a low SOC. This configuration allows charging of vehicles 10 with a high SOC to be completed in a short time, making it possible to open the charging station 130 early when there are vehicles 10 waiting to be charged.

[0035] Figure 5 is a timing chart illustrating the difference in procurement price depending on the charging schedule. For example, suppose that charging control unit 218 executes charging of vehicle 10 without any plan, without limiting the output power during the high price period. In this case, vehicle 10 can receive a supply of 54 kWh of power, as shown by the crosshatching, in a charging schedule in which the output power is maintained at 6 kW, as shown in Figure 5(a).

[0036] On the other hand, suppose that charging control unit 218 limits the output power during the high price period and charges vehicle 10. In this case, vehicle 10 is charged with an output power of 6 kW from 12:00 to 15:00 when charging starts in the charging schedule of Fig. 5(b), but is charged with an output power of 1.2 kW from 15:00 to 21:00, and is again charged with an output power of 6 kW from 21:00 to 25:48.

[0037] In this way, vehicle 10 can receive a supply of 54 kWh of electricity, as indicated by the crosshatching, according to the charging schedule in Figure 5(b). Note that if vehicle 10 is a taxi and charging station 130 is provided in power supply facility 100 corresponding to a business, the driver will often return to the facility after business hours to start charging vehicle 10 and leave it there until the next day. Therefore, in this case, although the charging time is 4 hours and 48 minutes longer than in the example in Figure 5(a), it is sufficient as long as charging starts after business hours, and the delayed charging completion time is not a significant problem.

[0038] Generally, the procurement price is expressed as market price (yen / kWh) x amount of electricity procured (kWh) + transmission and distribution network usage fee (yen). For the sake of convenience, we will only refer to market price x amount of electricity procured as the procurement price, and will omit the transmission and distribution network usage fee. Below, we will use Figures 3 to 5 to explain the difference in procurement price between when output power is not limited and when it is limited during high price periods.

[0039] First, let's calculate the procurement price if there are no restrictions on output power during high price periods. Referring to Figure 3, the market price from 12:00 to 15:00 is 10 yen / kWh, the market price from 15:00 to 18:00 is 30 yen / kWh, and the market price from 18:00 to 21:00 is 20 yen / kWh. Now, referring to Figure 5(a), the procurement price from 12:00 to 21:00 is calculated as 10 yen / kWh x 6kW x 3h + 30 yen / kWh x 6kW x 3h + 20 yen / kWh x 6kW x 3h = 1,080 yen.

[0040] On the other hand, if output power is limited during high price periods, the procurement price will be as follows: Referring to Figure 3, the market price from 12:00 to 15:00 is 10 yen / kWh, the market price from 15:00 to 18:00 is 30 yen / kWh, the market price from 18:00 to 21:00 is 20 yen / kWh, and the market price from 21:00 to 25:48 is 10 yen / kWh. Now, referring to Figure 5(b), the procurement price from 12:00 to 25:48 is calculated as follows: 10 yen / kWh x 6kW x 3h + 30 yen / kWh x 1.2kW x 3h + 20 yen / kWh x 1.2kW x 3h + 10 yen / kWh x 6kW x 4.8h = 648 yen.

[0041] It can be seen that limiting output power during high price periods results in significantly lower procurement prices than not limiting it. Therefore, limiting output power during high price periods will result in lower charging costs, even though it will increase charging time.

[0042] In this embodiment, as described above, when the driver desires to charge vehicle 10 and connects the charging connector to the charging port of vehicle 10, charging control unit 218 determines the charging schedule shown in Fig. 5(b) based on the power transition schedule shown in Fig. 4. This charging schedule involves charging at 6 kW from 12:00 when charging starts to 15:00, charging at 1.2 kW from 15:00 to 21:00, and charging at 6 kW from 21:00 to 25:48.

[0043] Next, the charging control unit 218 transmits output instructions (commands) based on the charging schedule to the charging stand 130 connected to the vehicle 10. Specifically, the charging control unit 218 issues a series of output instructions, such as setting the output power of the charging stand 130 to 6 kW at 12:00, reducing the output power of the charging stand 130 from 6 kW to 1.2 kW at 15:00, and increasing the output power of the charging stand 130 from 1.2 kW to 6 kW at 21:00. In this way, the output power of the charging stand 130 is 6 kW from 12:00 to 15:00, 1.2 kW from 15:00 to 21:00, and 6 kW from 21:00 to 25:48.

[0044] As described above, the charging control unit 218 determines the charging schedule without referring to the SOC of the vehicle 10, assuming that the SOC is 0. Therefore, depending on the SOC of the vehicle 10 at the start of charging and the maximum SOC of the battery, charging of the vehicle 10 may be completed earlier than the end time of the charging schedule.

[0045] In this case, the following event may occur. As described above, in the example of Fig. 5(b), the charging control unit 218 issues a series of output instructions, such as setting the output power of the charging stand 130 to 6 kW at 12:00, reducing the output power of the charging stand 130 from 6 kW to 1.2 kW at 15:00, and increasing the output power of the charging stand 130 from 1.2 kW to 6 kW at 21:00. Here, suppose that charging of the vehicle 10 is completed at 19:00, and then the fully charged vehicle 10 is moved. In this case, an output instruction remains in the charging stand 130, such as increasing the output power of the charging stand 130 from 1.2 kW to 6 kW at 21:00.

[0046] Suppose that another vehicle 10 subsequently starts charging at the same charging stand 130 from 8 p.m. In this case, the charging control unit 218 issues a series of output instructions, such as setting the output power of the charging stand 130 to 1.2 kW at 8 p.m. and increasing the output power of the charging stand 130 from 1.2 kW to 6 kW at 9 p.m. In this case, the output instructions to increase the output power of the charging stand 130 from 1.2 kW to 6 kW at 9 p.m. are duplicated, so the charging control unit 218 decides not to issue another output instruction to avoid duplication of output instructions.

[0047] When power control is performed based on a charging schedule, the longer the high price period, the more power consumption can be reduced when market prices are high, thereby reducing charging costs. Also, the lower the output power during the high price period, the more power consumption can be reduced when market prices are high, thereby reducing charging costs. However, extending the high price period or lowering the output power during the high price period results in a trade-off: longer charging times, which could result in the vehicle 10 not being fully charged by the time business hours open the next day.

[0048] Therefore, if extending the charging time of vehicle 10 does not affect the opening of business hours, charging control unit 218 extends the high price period or reduces the output power during the high price period. Furthermore, if extending the charging time of vehicle 10 would prevent charging from being completed in time for the opening of business hours, charging control unit 218 shortens the high price period or increases the output power during the high price period. The high price period is lengthened by lowering the predetermined value compared with the market price, and shortened by raising the predetermined value. By having charging control unit 218 perform such control in real time, it becomes possible to efficiently reduce charging costs while ensuring sufficient charging time.

[0049] (Output control of charging station 130) In the above-described embodiment, an example has been described in which the charging control unit 218 of the charging management server 200 determines the charging schedule for each charging stand 130 based on the charging progress schedule and controls the output of each charging stand 130 individually. However, in many cases, a plurality of charging stands 130 are installed in the power supply facility 100. If such a plurality of charging stands 130 are controlled independently, the total output power becomes large, which may cause the transformer 110 to fall into an overload state.

[0050] Therefore, the charging control unit 218 groups a plurality of charging stands 130 into charging stand groups, and performs overall control on a charging stand group basis.

[0051] The rated capacity of the transformer 110 of the power supply facility 100 is, for example, 50 kVA. While a 50 kVA rated capacity is illustrated here as an example of the rated capacity of the transformer 110, any rated capacity may be used. The maximum output power of the transformer 110 during overload operation is 50 kVA x 126%, or approximately 60 kVA. The overload operation conditions are an equivalent ambient temperature of 30°C and an overload operation time of one hour. The overload operation time is set to one hour because it is assumed that it takes approximately one hour from when the transformer 110 enters overload operation until an operator investigates the cause. Therefore, the power supply facility 100 can output a maximum of 60 kVA.

[0052] Here, the number of charging stations 130 (upper limit number) is determined based on the maximum capacity of the transformer 110 so that the maximum capacity of the transformer 110 will not be exceeded even if all charging stations 130 supply their maximum output power to their respective vehicles 10. In this way, (T / C) charging stations 130 with rated output power C are installed for the maximum capacity T of the transformer 110. For example, if the maximum capacity of the transformer 110 is 60 kVA as described above, 10 (= 60 / 6) charging stations 130 with rated output power of 6 kW can be installed. In this way, the power supply facility 100 can output a maximum of 60 kW (6 kW x 10 units) while suppressing deterioration of the insulating material of the windings of the transformer 110 due to overload operation.

[0053] As mentioned above, the rated capacity of the transformer 110 is 50 kVA. Therefore, in the power supply facility 100, it is preferable to limit the output power of the charging stands 130 to a maximum of 60 kW (6 kW x 10 stands), while limiting the total output power, which is the total amount of actual output power, to 50 kW or less. Here, the charging control unit 218 sets the total output power of the charging stands to a predetermined value of 50 kW or less, for example, 48 kW or less. This allows the transformer 110 to operate at its rated power.

[0054] Here, ten charging stands 130 are installed in the power supply facility 100, and the total output power of the charging stands as a group is limited to 48 kW. Control modes for limiting the total output power include equal-sharing control and first-come, first-served control. Below, equal-sharing control and first-come, first-served control will be explained in that order. Note that here, equal-sharing control and first-come, first-served control that limit the total output power of the ten charging stands 130 to 48 kW will be explained, but it goes without saying that the number of charging stands 130 and the total output power are not limited to these cases and can be set arbitrarily.

[0055] 6 is a flowchart for explaining the equal sharing control. The charging control unit 218 controls the output power of the charging stations 130 so that the output power of each of the charging stations 130 constituting the charging station group is a value obtained by proportionally dividing the total output power of 48 kW allowed for the charging station group in accordance with the ratio of the rated output power of each charging station 130 where charging is being performed. This equal sharing control is executed when a charging start signal and charging end signal are received.

[0056] (Step S100) The charging control unit 218 determines whether or not there is a vehicle 10 that has completed charging via the charging station 130. As a result, if there is a vehicle 10 that has completed charging (YES in S100), the charging control unit 218 proceeds to step S102, and if there is no vehicle 10 that has completed charging (NO in S100), the charging control unit 218 proceeds to step S112.

[0057] (Step S102) When it is determined that there is a vehicle 10 for which charging has been completed, the charging control unit 218 sets the output power of the charging station 130 connected to the vehicle 10 for which charging has been completed to 0 kW. In other words, the charging control unit 218 stops the output of power from the charging station 130. The charging control unit 218 also decrements the value of the charge number counter by 1 and deletes the charging station 130 from the charge list. The charge number counter is a counter that counts the number of charging stations 130 in which charging is in progress, and the charge list is a list that holds identifiers of charging stations 130 in which charging is in progress. Note that, although an example has been described in which the charging control unit 218 sets the output power of the charging station 130 connected to the vehicle 10 for which charging has been completed to 0 kW, the output power can be set to any value (for example, 1.2 kW) as long as the value is sufficiently smaller than 6 kW.

[0058] (Step S104) The charging control unit 218 determines whether the value of the charging number counter is 9. As a result, if the value of the charging number counter is 9 (YES in S104), the charging control unit 218 proceeds to step S106, and if the value of the charging number counter is not 9 (NO in S104), the charging control unit 218 proceeds to step S108.

[0059] (Step S106) The charging control unit 218 sets the output power of the nine charging stands 130 whose identifiers are held in the charging list to a value obtained by dividing the output power proportionally based on the ratio of their rated output powers. In this case, the rated output power of all charging stands 130 is 6 kW, so the value obtained by dividing the output power proportionally based on the ratio of their rated output powers is simply an average value obtained by dividing the total output power by the number of charging stands 130. Therefore, the charging control unit 218 sets the output power of the nine charging stands 130 to 5.3 kW, which is the total output power of 48 kW divided by nine. In this case, the number of charging stands 130 currently charging has decreased from 10 to 9, so the output power per stand can be increased from 4.8 kW to 5.3 kW.

[0060] (Step S108) The charging control unit 218 determines whether the value of the charging number counter is 8. As a result, if the value of the charging number counter is 8 (YES in S108), the charging control unit 218 proceeds to step S110, and if the value of the charging number counter is not 8 (NO in S108), the charging control unit 218 proceeds to step S112.

[0061] (Step S110) The charging control unit 218 sets the output power of the eight charging stations 130 whose identifiers are held in the charging list to 6 kW, which is the total output power of 48 kW divided by 8. In this case, the number of charging stations 130 in charging mode has decreased from 9 to 8, so the output power per station can be increased from 5.3 kW to 6 kW.

[0062] (Step S112) The charging control unit 218 determines, via the charging stand 130, whether or not there is a vehicle 10 that wishes to start charging. As a result, if there is a vehicle 10 that wishes to start charging (YES in S112), the charging control unit 218 proceeds to step S114, and if there is no vehicle 10 that wishes to start charging (NO in S112), the charging control unit 218 ends the equal sharing control. Note that the charging control unit 218 determines whether or not there is a vehicle 10 that wishes to start charging by, for example, detecting whether a charging connector, which is an end of an on-board charging cable, is connected to a charging port of the vehicle 10. Alternatively, the charging control unit 218 may determine whether or not there is a vehicle 10 that wishes to start charging by detecting, via a camera or infrared sensor provided in the charging stand 130, whether or not there is a vehicle 10 in a predetermined charging area corresponding to the charging stand 130.

[0063] (Step S114) When it is determined that there is a vehicle 10 that wishes to start charging, the charging control unit 218 increments the value of the charging number counter by 1 and adds the charging station 130 to the charging list.

[0064] (Step S116) The charging control unit 218 determines whether the value of the charging number counter is 10. As a result, if the value of the charging number counter is 10 (YES in S116), the charging control unit 218 proceeds to step S118, and if the value of the charging number counter is not 10 (NO in S116), the charging control unit 218 proceeds to step S120.

[0065] (Step S118) The charging control unit 218 sets the output power of all charging stations 130 to 4.8 kW, which is the total output power of 48 kW divided by 10 stations, and ends the equal distribution control. Here, the number of charging stations 130 in charging mode has increased from 9 to 10 stations, so the output power per station must be reduced from 5.3 kW to 4.8 kW.

[0066] (Step S120) The charging control unit 218 determines whether the value of the charging number counter is 9. As a result, if the value of the charging number counter is 9 (YES in S120), the charging control unit 218 proceeds to step S122, and if the value of the charging number counter is not 9 (NO in S120), the charging control unit 218 proceeds to step S124.

[0067] (Step S122) The charging control unit 218 sets the output power of the nine charging stations 130 whose identifiers are held in the charging list to 5.3 kW, which is the total output power of 48 kW divided by 9. In this case, the number of charging stations 130 in the charging state has increased from 8 to 9, so the output power per station must be reduced from 6 kW to 5.3 kW.

[0068] (Step S124) The charging control unit 218 sets the output power of the charging station 130 added to the charging list in step S114 to 6 kW. Here, since there are eight or fewer charging stations 130 currently charging, the output power per station can be maintained at 6 kW. Therefore, the output power of the added charging station 130 can be set to 6 kW.

[0069] In this way, the charging control unit 218 can evenly distribute the total output power of 48 kW permitted for the charging station group among the charging stations 130 where charging is being performed.

[0070] Note that, in the example described above, it is assumed that the rated output power of each charging stand 130 is equal to 6 kW, and the charging control unit 218 sets the output power of the charging stand 130 where charging is being performed to a value obtained by dividing the total output power of 48 kW by the number of charging stands 130. However, if the rated output powers of the charging stands 130 are different, the charging control unit 218 sets the output power of the charging stand 130 where charging is being performed to a value proportionally divided by the ratio of the rated output powers of the charging stands 130. For example, if the rated output power of five charging stands 130 is 6 kW and the rated output power of the remaining five charging stands 130 is 3 kW, the charging control unit 218 divides the total output power proportionally between the charging stands 130 with a rated output power of 6 kW and the charging stands 130 with a rated output power of 3 kW, i.e., 2:1. Specifically, if the total output power is 30 kW, the charging control unit 218 sets the rated output power of five charging stands 130 with 6 kW to 4 kW, and sets the rated output power of five charging stands 130 with 3 kW to 2 kW. In this case, the total output power is 4 kW x 5 stands + 2 kW x 5 stands = 30 kW.

[0071] FIG. 7 is a flowchart illustrating first-come, first-served control. In first-come, first-served control, a maximum output power of 6 kW is supplied to only eight vehicles in the order in which charging starts (first-served). Specifically, when the total output power is equal to or less than a predetermined value, for example, 48 kW, the charging control unit 218 sets the output power to the charging stand 130 in the order in which charging requests are received. When the total output power exceeds the predetermined value, the charging control unit 218 does not set the output power to the charging stand 130 even if a charging request is received (sets the output power to 0 kW). This first-come, first-served control is executed when the charging start signal and end signal are received. Note that, in the example described above, the charging control unit 218 does not set the output power to the charging stand 130 even if a charging request is received when the total output power exceeds the predetermined value (sets the output power to 0 kW). However, the output power can be set to any value (for example, 1.2 kW) as long as it is sufficiently smaller than 6 kW. In this way, by setting a sufficiently small value as the output power, it is possible to determine that power is being supplied from the charging stand 130 as described above, and to distinguish this from a malfunction of the charging stand 130.

[0072] (Step S150) The charging control unit 218 determines whether or not there is a vehicle 10 that wishes to start charging via the charging stand 130. As a result, if there is a vehicle 10 that wishes to start charging (YES in S150), the charging control unit 218 proceeds to step S152, and if there is no vehicle 10 that wishes to start charging (NO in S150), the charging control unit 218 proceeds to step S158. As described above, the charging control unit 218 determines whether or not there is a vehicle 10 that wishes to start charging by, for example, detecting whether a charging connector is connected to a charging port of the vehicle 10.

[0073] (Step S152) When it is determined that there is a vehicle 10 that wishes to start charging, the charging control unit 218 increments the value of the charging number counter by 1 and adds the charging station 130 to the charging list in association with the desired charging time, which is the time when the vehicle 10 wishes to start charging.

[0074] Here, the reason why the charging station 130 is associated with the desired charging time is to allow a vehicle 10 with an earlier desired charging time to start charging before a vehicle 10 with a later desired charging time. For example, if eight of ten charging stations 130 are already charging at the desired charging time, the total output power reaches 48 kW, and the vehicle 10 is placed in a charging standby state and cannot start charging. Under such circumstances, when the other vehicles 10 complete charging, charging at the charging station 130 can start for one vehicle 10. At this time, the charging control unit 218 starts charging, starting with the vehicle 10 with the earliest desired charging time among the vehicles 10 waiting to be charged. Note that if there are fewer than eight charging stations 130 currently charging (the charging number counter is ≦8), the vehicle 10 can start charging without waiting to be charged. In this case, the charging station 130 may be associated with a charging start time, which is the time when the vehicle 10 actually started charging, instead of the desired charging time, and added to the charging list. In addition, here, the order in which requests for charging are received has been exemplified as being in the order of the earliest desired charging time, but this is not limited to this case. For example, the order may be in the order of the earliest time the charging connector was connected to the charging port of vehicle 10, the earliest time a reservation for charging was made, the earliest time a request to start charging was made, or any other order in which vehicle 10 became ready for charging.

[0075] (Step S154) The charging control unit 218 determines whether the value of the charging number counter is equal to or less than 8. As a result, if the value of the charging number counter is equal to or less than 8 (YES in S154), the charging control unit 218 proceeds to step S156, and if the value of the charging number counter is greater than 8 (NO in S154), the charging control unit 218 proceeds to step S158.

[0076] (Step S156) The charging control unit 218 sets the output power of the charging station 130 added to the charging list in step S152 to 6 kW. In this case, because there are eight or fewer charging stations 130 currently charging, the total output power can be kept to 48 kW or less even if a new charging station 130 starts. Therefore, the output power of the added charging station 130 can be set to 6 kW.

[0077] In this configuration, if there are nine or more vehicles 10, charging will not start for one or two of the vehicles 10. However, as described above, if the vehicles 10 are taxis and the charging stations 130 are provided in the power supply facility 100 corresponding to a business establishment, drivers often start charging their vehicles 10 after business hours have ended and leave them there until the next day, so it is sufficient for charging to start after business hours have ended, and delaying the charging end time does not pose much of a problem.

[0078] (Step S158) The charging control unit 218 determines whether or not there is a vehicle 10 that has completed charging through the charging station 130. As a result, if there is a vehicle 10 that has completed charging (YES in S158), the charging control unit 218 proceeds to step S160, and if there is no vehicle 10 that has completed charging (NO in S158), the charging control unit 218 ends the first-come, first-served process.

[0079] (Step S160) When it is determined that charging has been completed for a vehicle 10, the charging control unit 218 sets the output power of the charging station 130 connected to the vehicle 10 that has been charged to 0 kW. The charging control unit 218 also decrements the value of the charge number counter by 1 and deletes the charging station 130 from the charging list.

[0080] (Step S162) The charging control unit 218 determines whether the value of the charge number counter is equal to or greater than 8. As a result, if the value of the charge number counter is equal to or greater than 8 (YES in S162), the charging control unit 218 proceeds to step S164, and if the value of the charge number counter is less than 8 (NO in S162), the first-come, first-served process ends.

[0081] (Step S164) The charging control unit 218 references the desired charging time in the charging list and sets the output power of the charging station 130 with the eighth earliest desired charging time to 6 kW. In this case, because there are eight or more charging stations 130 currently charging, charging can be started at one charging station 130 in place of the charging station 130 for which charging has completed. There may be one or two vehicles 10 waiting to be charged, but the output power of the charging station 130 with the earliest desired charging time, i.e., the charging station 130 with the eighth earliest desired charging time, can be set to 6 kW.

[0082] In this way, the charging control unit 218 can supply the maximum output power of 6 kW only to eight units in the order in which charging starts (first come, first served).

[0083] Also, here, an example has been described in which, when a vehicle 10 wishes to start charging, the charging control unit 218 associates the desired charging time with the charging stand 130 of the vehicle 10 and adds the charging stand 130 to the charging list. However, this is not the only case, and when a vehicle 10 wishes to start charging, the charging control unit 218 may assign a number to the charging stand 130 and control the start of charging.

[0084] In this way, the charging control unit 218 refers to the desired charging times at which the vehicles 10 have requested to start charging, directly compares the desired charging times, and sets the output power of the charging stations 130 in order of the earliest desired charging time. However, this is not limiting, and the charging control unit 218 may associate a number with the charging start time and manage the order in which the vehicles 10 have requested to start charging using the numbers instead of the charging start time. For example, the charging control unit 218 assigns numbers from 1 to 10 to the charging stations 130 in ascending order in order of the earliest time at which the vehicles 10 have requested to start charging. Then, when charging of any vehicle 10 is completed, the charging control unit 218 deletes the number associated with the charging station 130 for which charging has been completed, and decrements (shifts) all numbers greater than that number by one.

[0085] FIG. 8 is an explanatory diagram showing an example in which the charging control unit 218 controls the start of charging using numbers. For example, as shown in FIG. 8(a), assume that ten vehicles 10 wish to start charging. Therefore, the charging stations 130 are numbered 1 to 10 in the order in which the vehicles 10 wish to start charging. In this example, since only eight charging stations 130 can perform charging, as shown by the outlined arrows, the vehicles 10 are charging at charging stations 130 numbered 1 to 8, which are the earliest vehicles 10 wished to start charging, respectively. Furthermore, as shown by the solid black arrows, the vehicles 10 are waiting to be charged at charging stations 130 numbered 9 and 10, which are the latest vehicles 10 wished to start charging, respectively. Here, as shown in FIG. 8(b), when charging is completed at charging station 130 numbered 5, station number 5 is deleted, and stations numbered 1 to 4 are maintained, while stations numbered 6, 7, 8, 9, and 10 are decremented by one, becoming stations numbered 5, 6, 7, 8, and 9, respectively. At this time, the charging station 130 numbered 9 becomes number 8 and can start charging the vehicle 10. Then, as shown in Figure 8(c), when a new vehicle 10 wishes to start charging at the charging station 130 that was assigned number 5 in Figure 8(a) and where no vehicle 10 wishes to start charging, the charging station 130 is assigned number 10, which is the number after number 9, and the vehicle 10 in question waits for charging.

[0086] The charging control unit 218 can also manage the numbers without performing decrements. For example, the charging control unit 218 assigns numbers from 1 to 100 to the charging stations 130 in ascending order, in order of the earliest time that the vehicle 10 requested to start charging. Then, when charging of any vehicle 10 is completed, the charging control unit 218 deletes the number associated with the charging station 130 where charging has been completed, but does not decrement numbers greater than that number.

[0087] FIG. 9 is an explanatory diagram showing another example in which the charging control unit 218 controls the start of charging using numbers. For example, as shown in FIG. 9(a), assume that ten vehicles 10 wish to start charging. Therefore, the charging stations 130 are numbered 1 to 10 in the order in which the vehicles 10 wish to start charging. In this example, since only eight charging stations 130 can perform charging, as shown by the outlined arrows, the vehicles 10 are charging at charging stations 130 numbered 1 to 8, which are the earliest charging stations in which the vehicles 10 wished to start charging. Furthermore, as shown by the solid black arrows, the vehicles 10 are waiting to be charged at charging stations 130 numbered 9 and 10, which are the latest charging stations in which the vehicles 10 wished to start charging. Here, as shown in FIG. 9(b), when charging is completed at charging station 130 numbered 5, station 5 is deleted, but stations 1 to 4 and stations 6 to 10 remain unchanged. After station 5 is deleted, station 9 becomes the eighth of the numbered charging stations, and charging of the vehicles 10 can begin. Then, as shown in FIG. 9(c), when a new vehicle 10 requests to start charging at a charging station 130 that was assigned number 5 in FIG. 9(a) and has no vehicles 10 requesting to start charging, the charging station 130 is assigned number 11, which is the number after number 10, and the vehicle 10 is placed on standby for charging. Note that if a vehicle 10 requests to start charging after number 100, the charging station 130 is assigned the starting number 1. In this case, the timing at which the vehicle 10 requested to start charging at number 100 is earlier than that at number 100. With this configuration, although there are more numbers to manage than in the example using numbers 1 to 10, the processing load can be reduced by not performing decrements.

[0088] As described above, the total output power of the charging groups can be kept below 48 kW by using equal sharing control and first-come, first-served control. However, if communication between the charging management server 200 and the charging stand 130 is unstable or if there is some kind of malfunction on the power supply facility 100 side, the total output power of the charging groups may exceed 50 kW. Therefore, the charging system 1 monitors, via the power meter 120, whether the total output power is being maintained.

[0089] For example, the information acquisition unit 212 of the charging management server 200 acquires an instantaneous power measurement value from the power meter 120 for a predetermined first period, for example, at 10-minute intervals, and determines whether the instantaneous power measurement value exceeds 48 kW. If it is determined that the instantaneous power measurement value exceeds 48 kW, the charging control unit 218 resets the current output power for all charging stands 130.

[0090] Furthermore, the information acquisition unit 212 acquires instantaneous power measurement values ​​from the power meter 120 at predetermined second intervals, for example, at 20-minute intervals, and determines whether the instantaneous power measurement values ​​exceed 48 kW. If it is determined that the instantaneous power measurement values ​​exceed 48 kW, the charging control unit 218 sets the output power for all charging stands 130 to 0 kW, i.e., stops the output power of the charging stands 130, and records the fact that they have been stopped in a log. Based on the log, an operator investigates the reason why the total output power exceeded 48 kW.

[0091] Furthermore, if communication between the charging management server 200 and the charging stand 130 is unstable, output instructions from the charging control unit 218 may not be transmitted normally to the charging stand 130, and equal-share control or first-come-first-served control may not be performed appropriately. Therefore, a control device that comprehensively controls the multiple charging stands 130 may be provided on the power supply facility 100 side. In this case, the control device realizes the functions of equal-share control and first-come-first-served control of the charging control unit 218 in the charging management server 200.

[0092] With this configuration, the equal-share control and first-come-first-served control can be performed entirely on the power supply facility 100 side. Therefore, even if communication between the charging management server 200 and the charging stand 130 becomes unstable, the equal-share control and first-come-first-served control can be appropriately performed, and the total output power can be kept below 48 kW. In this case, the control device of the power supply facility 100 may monitor the instantaneous power measurement value via the power meter 120.

[0093] Note that the example described here is one in which the charging management server 200 remotely controls one charging station group formed by grouping ten charging stations 130. However, because it is remote control, there are no restrictions on the location of the charging management server 200 or the number of charging station groups that can be controlled, as long as communication is possible. For example, the charging management server 200 can remotely control multiple charging station groups located in different locations at once. In this case, the charging management server 200 may remotely control each of the multiple charging station groups independently, or may remotely control the multiple charging station groups collectively.

[0094] In the former case, the charging control unit 218 performs equal-sharing control or first-come-first-served control, for example, so that the total output power of the first charging station group is a predetermined value of 50 kW or less, for example, 48 kW or less. Independently, the charging control unit 218 performs equal-sharing control or first-come-first-served control, for example, so that the total output power of the second charging station group is a predetermined value of 50 kW or less, for example, 48 kW or less. In this way, charging of the vehicle 10 can be appropriately performed for each charging station group. On the other hand, in the latter case, the charging control unit 218 performs equal-sharing control or first-come-first-served control, for example, so that the total output power of the first charging station group and the second charging station group combined is a predetermined value of 100 kW or less, for example, 98 kW or less. With this configuration, when there are more vehicles 10 wishing to charge at the second group of charging stations than at the first group of charging stations, the charging control unit 218 performs, for example, equal-share control or first-come, first-served control so that the total output power of the first group of charging stations is 40 kW or less, and simultaneously performs equal-share control or first-served control so that the total output power of the second group of charging stations is 58 kW or less. With this configuration, it becomes possible to efficiently charge vehicles 10 while suppressing the total output power of the first group of charging stations and the second group of charging stations combined.

[0095] Furthermore, in the above-described embodiment, an example has been described in which a plurality of (e.g., 10) charging stands 130 equivalent to normal chargers are installed in the power supply facility 100. However, this is not the only case, and charging stands equivalent to quick chargers may be installed in the power supply facility 100 instead of or in addition to the charging stands 130 equivalent to normal chargers.

[0096] In this case, the charging control unit 218 may independently manage a group of charging stations 130 equivalent to normal chargers and a group of charging stations equivalent to rapid chargers, and prioritize charging at one of the charging station groups. For example, if the charging control unit 218 prioritizes the use of a group of charging stations equivalent to rapid chargers and sets 40 kW for the group of charging stations equivalent to rapid chargers, it sets 8 (48-8) kW for the group of charging stations 130 equivalent to normal chargers. In this way, even when there are mixed groups of charging stations, it is possible to keep the total output power at 48 kW or less.

[0097] Furthermore, the output control of the charging stations 130 based on the equal distribution control or first-come, first-served control can be applied to the charging schedule management described with reference to Figures 3 to 5. In the above, an example has been described with reference to Figures 3 to 5 in which the charging control unit 218 limits the output power of each charging station 130 individually. Alternatively, the charging control unit 218 may manage the charging stations 130 as a group of charging stations and limit the total output power. For example, the charging control unit 218 controls the total output power of the group of charging stations to be 48 kW or less, and during high price periods, controls the total output power of the group of charging stations to be 9.6 (48 / 5) kW or less.

[0098] This configuration allows power control based on the charging schedule for each charging station group, reducing overall charging costs. It also prevents the total output power from becoming 60 kW when the high-price period ends, preventing all charging stations 130 from outputting 6 kW.

[0099] In the above-described embodiment, an example has been described in which output control of the charging stand 130 is applied to the power supply facility 100 corresponding to a taxi business. However, this is not limited to this case, and output control of the charging stand 130 can be applied to various facilities as the power supply facility 100. Here, the facility may be an entire building or a part of a building, such as a hospital, factory, hotel, leisure facility, commercial facility, or apartment building, or an entire site or a part of a site, such as a convenience store, supermarket, or restaurant. With this configuration, it is possible to execute output control of the charging stand 130 on a facility-by-facility basis.

[0100] Furthermore, when the output control of the charging stand 130 is applied to a facility in this manner, the charging management server 200 can manage the total output power of the group of charging stands installed in the facility in cooperation with the facility's EMS (Energy Management System). For example, the information acquisition unit 212 of the charging management server 200 acquires the load of the facility in real time from the facility's EMS. The charging control unit 218 controls the output of the charging stand 130 with respect to the chargeable power, which is the power obtained by subtracting the load of the facility from the contracted power under the contract for the facility. In other words, the charging control unit 218 performs tracking control so that the total output power of the group of charging stands installed in the facility is equal to or less than the chargeable power, thereby making it possible to keep the power of the facility equal to or less than the contracted power.

[0101] In addition, when the total output power must be set low due to the load of the facility, the charging control unit 218 can not only reduce the output power of the charging stand 130, but also apply other methods to reduce the output power, such as not accepting charging reservations for a specified period of time.

[0102] Furthermore, the charging system 1 can also collect compensation (charging fee) for charging through the charging station 130 from the driver of the vehicle 10. The charging control unit 218 may calculate a compensation proportional to the time, for example, based on the time required to charge the vehicle 10 at each charging station 130, and bill the driver of the vehicle 10 for the compensation.

[0103] However, when the charging schedule management described with reference to Figures 3 to 5 is applied, the output power of the charging station 130 will differ between high price periods and periods other than the high price periods. Since charging takes a relatively long time during high price periods when output power is limited, if the charging system 1 were to uniformly charge a fee proportional to the time required to charge the vehicle 10, the driver would feel a sense of unfairness. Therefore, here, a fee commensurate with the output power is charged.

[0104] FIG. 10 is a block diagram illustrating another example of the charging system 1. First, in the charging system 1, in addition to the power meter 120, a meter 140 that measures power is installed at each charging stand 130. The charging control unit 218 calculates a fee for charging the vehicle 10 at each charging stand 130 based on the amount of power (kWh) measured by the meter 140, for example, proportional to the amount of power measured by the meter 140, and charges the fee to the driver of the vehicle 10. A configuration including such a meter 140 is highly effective when applied to a quick charger, but can also be applied to a normal charger. With this configuration, even if the output power of the charging stand 130 is limited during a high-price period, the amount of power is measured at a correspondingly lower value, so the charging control unit 218 can charge a fee commensurate with the amount of power charged.

[0105] Furthermore, if meter 140 were located closer to the power grid than transformer 110, a power loss of, for example, 5% would occur between that point and charging stand 130. In this case, a difference would occur between the amount of power actually supplied to vehicle 10 and the amount of power measured by meter 140, which would cause the driver to feel a sense of unfairness. Here, meter 140 is provided at charging stand 130 immediately before power is output, making it possible to improve the accuracy of measuring the amount of power.

[0106] In this way, the charging management device (e.g., charging management server 200) includes a schedule generation unit 216 that references a high price period in which the average value of the reference price of electricity (e.g., market price) is higher than other periods, and generates a power transition schedule that reduces the output power of a charger (e.g., charging stand 130) after the start of the high price period compared to the output power of the charger before the start of the high price period and increases the output power of the charger after the end of the high price period compared to the output power of the charger before the end of the high price period, and a charging control unit 218 that controls the output power of the charger based on the power transition schedule. With this configuration, it becomes possible to reduce charging costs, although the charging time will be slightly longer.

[0107] A charger group (e.g., a charging station group) may be configured with a plurality of chargers (e.g., charging stations 130), and the charging control unit 218 may control the output power of the chargers so that the total output power, which is the sum of the output power of the chargers that make up the charger group, is equal to or less than a predetermined value (e.g., 48 kW). With this configuration, it becomes possible to efficiently charge the vehicle 10 while suppressing the total output power. Furthermore, since it becomes possible for the charging station group to output power up to the total output power, the vehicle 10 can be charged more frequently, and charging efficiency can be improved.

[0108] The charging control unit 218 may control the output power of the chargers (e.g., charging stations 130) that make up a group of chargers (e.g., a group of charging stations) so that the output power of each charger is a predetermined value (e.g., 48 kW) divided proportionally in proportion to the rated output power of each charger (e.g., charging station 130) where charging is being performed. With this configuration, the charging control unit 218 can evenly distribute the total output power of 48 kW allowed for the group of charging stations among the charging stations 130 where charging is being performed.

[0109] When the total output power is equal to or less than a predetermined value (e.g., 48 kW), the charging control unit 218 may set the output power to the chargers (e.g., charging stands 130) in the order in which charging becomes possible (e.g., the earliest desired charging time), and when the total output power exceeds the predetermined value, the charging control unit 218 may not set the output power to the chargers even if charging becomes possible. With this configuration, the charging control unit 218 can supply a maximum output power of 6 kW to only a predetermined number of units, for example, 8 units, in the order in which charging started first (first come, first served).

[0110] Furthermore, in the charging management method, the computer references a high price period in which the average value of the reference price of electricity (e.g., market price) is higher than other periods, generates a power transition schedule that reduces the output power of the charger (e.g., charging stand 130) after the start of the high price period compared to the output power of the charger before the start of the high price period and increases the output power of the charger after the end of the high price period compared to the output power of the charger before the end of the high price period, and reduces the output power of the charger at the start of the high price period and increases the output power of the charger at the end of the high price period based on the power transition schedule. With this configuration, it is possible to reduce charging costs, although charging time will be slightly longer.

[0111] Furthermore, the charging management device (e.g., charging management server 200) is communicatively connected to chargers (e.g., charging stations 130) that make up a group of chargers (e.g., a group of charging stations), and includes a charging control unit 218 that remotely controls the output power of the chargers, and the charging control unit 218 controls the output power of the chargers so that the total output power, which is the sum of the output power of the chargers that make up the group of chargers, is equal to or less than a predetermined value (e.g., 48 kW). With this configuration, it becomes possible to efficiently charge the vehicle 10 while suppressing the total output power. Furthermore, since it becomes possible for the group of charging stations to output power up to the total output power, the vehicle 10 can be charged more frequently, and charging efficiency can be improved.

[0112] Furthermore, in the charging management method, a computer controls the output power of chargers so that the total output power, which is the sum of the output power of chargers (e.g., charging stations 130) that make up a group of chargers (e.g., a group of charging stations), is equal to or less than a predetermined value. With this configuration, it becomes possible to efficiently charge the vehicle 10 while suppressing the total output power. Furthermore, since it becomes possible for the group of charging stations to output power up to the total output power, the vehicle 10 can be charged more frequently, and charging efficiency can be improved.

[0113] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such embodiments. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that such modifications and alterations also fall within the technical scope of the present invention.

[0114] For example, in the above-described embodiment, an example was described in which a so-called electricity retailer through an electricity market, which procures wholesale power from an electricity market and sells the power through the charging station 130, manages the charging system 1 and uses the market price as the target base price. However, the charging system 1 can be managed by various types of businesses, such as electricity retailers that procure power directly from power plants without going through an electricity market, and consumers, in addition to such electricity retailers through an electricity market. For example, when an electricity retailer that procures power directly through a bilateral contract with a power plant or through an off-site power purchase agreement (PPA) manages the charging system 1, the electricity retailer directly procures wholesale power at a procurement price that takes into account the consumer's power demand and the power supply of the power plant. Here, the procurement price is used as the base price instead of the market price. Therefore, the charging management server 200 can reduce charging costs by suppressing charging when the procurement price is high in response to fluctuations in the procurement price. In this case, dynamic pricing can be applied, in which the procurement price fluctuates based on the consumer's demand at the time of wholesale power procurement.

[0115] Furthermore, when a business operator manages the charging system 1 as a consumer, the market price adjustment unit price is used as the base price instead of the market price, as follows. For example, taking into account the fluctuations in market prices in the electricity market described above, the electricity charge paid by a consumer receiving electricity from the power grid is the basic charge + energy charge + fuel cost adjustment + market price adjustment unit price + renewable energy generation promotion levy. The market price adjustment unit price (yen / kWh) reflects fluctuations in the market price every 30 minutes in the electricity bill. For the sake of convenience, only the market price adjustment unit price will be mentioned here, and the difference in electricity charges between when output power is not limited during high price periods and when it is limited will be explained using Figures 3 to 5.

[0116] First, let's calculate the market price adjustment unit price if output power during the high price period is not limited. Here, let's assume that the base market price is 15 yen / kWh and the adjustment coefficient is 0.5. Referring to Figure 3, the market price adjustment unit price from 12:00 to 15:00 is (10 (market price) - 15 (base market price)) x 0.5 (adjustment coefficient) = -2.5 yen / kWh. The market price adjustment unit price from 15:00 to 18:00 is (30 - 15) x 0.5 = 7.5 yen / kWh. The market price adjustment unit price from 18:00 to 21:00 is (20 - 15) x 0.5 = 2.5 yen / kWh. Referring to Figures 4 and 5(a), the electricity rate for the market price adjustment unit price from 12:00 to 21:00 is calculated as follows: -2.5 yen / kWh x 6kW x 3h + 7.5 yen / kWh x 6kW x 3h + 2.5 yen / kWh x 6kW x 3h = 135 yen.

[0117] On the other hand, if output power is limited during high price periods, the market price adjustment unit price will be as follows: Referring to Figure 3, the market price adjustment unit price from 12:00 to 15:00 = (10 - 15) x 0.5 = -2.5 yen / kWh, the market price adjustment unit price from 15:00 to 18:00 = (30 - 15) x 0.5 = 7.5 yen / kWh, the market price adjustment unit price from 18:00 to 21:00 = (20 - 15) x 0.5 = 2.5 yen / kWh, and the market price adjustment unit price from 21:00 to 25:48 = (10 - 15) x 0.5 = -2.5 yen / kWh. Here, referring to Figures 4 and 5(b), the electricity charge related to the market price adjusted unit price from 12:00 to 25:48 is calculated as -2.5 yen / kWh x 6kW x 3h + 7.5 yen / kWh x 1.2kW x 3h + 2.5 yen / kWh x 1.2kW x 3h - 2.5 yen / kWh x 6kW x 4.8h = -81 yen.

[0118] Here, it can be seen that limiting output power during high price periods results in significantly lower electricity rates related to the market price adjusted unit price than not limiting it. Therefore, just as with the case of using market prices, limiting output power during high price periods will make it possible to reduce charging costs, although charging time will be slightly longer.

[0119] The steps of the equal distribution control and first-come-first-served control do not necessarily have to be processed in chronological order according to the order shown in the flowchart, and may include parallel processing or subroutine processing. [Explanation of symbols]

[0120] 1 Charging System 10 vehicles 100 Power supply equipment 110 Transformer 120 Electricity Meter 130 Charging stand (charger) 200 Charging management server (charging management device) 210 Server Communication Department 212 Information Acquisition Department 214 Period Determination Department 216 Schedule Generation Unit 218 Charging control unit

Claims

1. a schedule generating unit that generates a power transition schedule that references a high price period in which the average value of the reference price of electricity is higher than other periods, and that reduces the output power of the charger after the start of the high price period compared to the output power of the charger before the start of the high price period, and that increases the output power of the charger after the end of the high price period compared to the output power of the charger before the end of the high price period; a charge control unit that controls the output power of the charger based on the power transition schedule; A charge management device comprising:

2. A plurality of the chargers constitute a charger group, The charge management device according to claim 1 , wherein the charge control unit controls the output power of the chargers so that a total output power, which is a total amount of output power of the chargers constituting the charger group, is equal to or less than a predetermined value.

3. 3. The charging management device according to claim 2, wherein the charging control unit controls the output power of the chargers so that the output power of each of the chargers constituting the charger group becomes a value obtained by dividing the predetermined value proportionally in proportion to the rated output power of each of the chargers being charged.

4. The charging control unit If the total output power is equal to or less than the predetermined value, the output power is set to the chargers in the order in which they become ready for charging; The charge management device according to claim 2 , wherein when the total output power exceeds the predetermined value, no output power is set for the charger even if charging becomes possible.

5. The computer Refers to high price periods when the average value of the base price of electricity is higher than other periods, generating a power transition schedule that reduces the output power of the charger after the start of the high price period below the output power of the charger before the start of the high price period and increases the output power of the charger after the end of the high price period above the output power of the charger before the end of the high price period; based on the power transition schedule, reducing the output power of the charger at a start timing of the high price period and increasing the output power of the charger at an end timing of the high price period; Charging management method.

Images