Charging system

Abstract

To provide a charging system capable of automatically adjusting a target demand to an appropriate value.SOLUTION: A charging system A1 includes: a plurality of charging devices 2 that charge a storage battery 54 of an electric mobile object 5 that moves by driving an electric motor with electric power of the storage battery 54; and a charging control device 1 that controls the plurality of charging devices 2. The charging control device 1 includes: a power control unit 112 that controls overall output power based on a target demand; a full charge determination unit 115 that determines whether or not charging of the connected storage battery 54 is completed for each of the plurality of charging devices 2; a rate detection unit 116 that detects a full charging rate that is a rate of the charging device 2 that have completed charging; and a target demand adjusting unit 117 that adjusts the target demand based on the full charging rate.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a charging system including a plurality of charging devices for charging electric vehicles and the like.

Background Art

[0002] In recent years, with the spread of electric vehicles, the development of charging systems for charging the batteries of electric vehicles has been progressing. The charging system includes a plurality of charging devices and a charging control device for controlling them. Further, the charging system may be incorporated into energy management in the facility where it is installed. In this case, the charging control device is input with a target demand from a higher-level device that performs energy management, and controls so that the output power of the charging system does not exceed the target demand. Patent Document 1 discloses a demand controller that monitors a demand value based on a measured value of power consumption and adjusts the load so that the demand value does not exceed the target demand.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, in a charging system installed in an apartment building, each charging station is connected to a resident's electric vehicle, and charging takes place overnight. In this case, there is no problem as long as charging is completed by morning, so it is possible to distribute the power consumption. However, since the charging control device controls the output power of the charging system based on the input target demand, it was necessary to manually change the target demand in order to distribute the power consumption. When changing the target demand manually, if it is reduced too much, charging may be insufficient by morning, potentially affecting the use of electric vehicles. Setting an appropriate target demand manually is difficult and also a cumbersome task.

[0005] This invention was conceived under the circumstances described above, and its purpose is to provide a charging system that can automatically adjust the target demand to an appropriate value. [Means for solving the problem]

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

[0007] A charging system provided by a first aspect of the present invention comprises a plurality of charging devices for charging the battery of an electric mobile body that moves by driving an electric motor with the power of the battery, and a charging control device for controlling the plurality of charging devices, wherein the charging control device comprises a power control unit for controlling the total output power based on a target demand, a full charge determination unit for determining whether or not the connected battery has been fully charged for each of the plurality of charging devices, a ratio detection unit for detecting a full charge ratio which is the percentage of charging devices that have completed charging, and a target demand adjustment unit for adjusting the target demand based on the full charge ratio.

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

[0009] In a preferred embodiment of the present invention, the target demand adjustment unit decreases the target demand when the full charge ratio is equal to or greater than a first ratio, and increases the target demand when the full charge ratio is less than a second ratio.

[0010] In a preferred embodiment of the present invention, the target demand adjustment unit decreases the target demand by a first set value when decreasing it, and increases the target demand by a second set value smaller than the first set value when increasing it.

[0011] In a preferred embodiment of the present invention, the target demand adjustment unit sets the lower limit to the target demand if the reduced target demand is below the lower limit, and sets the upper limit to the target demand if the increased target demand is above the upper limit.

[0012] In a preferred embodiment of the present invention, the charging control device further comprises a charging demand detection unit that detects the charging demand, which is the demand value of the power output by each of the plurality of charging devices at the demand time limit, and an abnormality detection unit that detects the occurrence of an abnormality in each of the plurality of charging devices, and the full charge determination unit determines that the charging of the connected storage battery is complete for charging devices in which the detected charging demand is less than or equal to a determination standard value and no abnormality is detected.

[0013] In a preferred embodiment of the present invention, the system further includes an index acquisition unit that acquires induction indicators input from a higher-level device that manages the charging control device, and a target demand calculation unit that uses the induction indicators to calculate the target demand based on a pre-set optimization problem.

[0014] A charging system provided by a second aspect of the present invention comprises a plurality of charging devices for charging the battery of an electric mobile body that moves by driving an electric motor with the power of the battery, and a charging control device for controlling the plurality of charging devices, wherein the charging control device comprises a full charge determination unit for each of the plurality of charging devices that determines whether or not the charging of the connected battery has been completed, a charging demand detection unit that detects the charging demand, which is the demand value at the demand time limit of the power output by each of the plurality of charging devices, and an abnormality detection unit that detects the occurrence of an abnormality in each of the plurality of charging devices, wherein the full charge determination unit determines that the charging of the connected battery has been completed for charging devices in which the detected charging demand is less than or equal to a determination criterion value and no abnormality has been detected. [Effects of the Invention]

[0015] According to the present invention, a full charge determination unit determines whether or not charging is complete for each charging device, and a ratio detection unit detects the full charge ratio, which is the percentage of charging devices that have completed charging. Then, a target demand adjustment unit adjusts the target demand based on the full charge ratio. Therefore, the charging control device can automatically adjust the target demand to an appropriate value by decreasing the target demand when the full charge ratio is large and increasing the target demand when the full charge ratio is small.

[0016] Other features and advantages of the present invention will become more apparent from the detailed description below with reference to the accompanying drawings. [Brief explanation of the drawing]

[0017] [Figure 1] This is a block diagram showing the overall configuration of the charging system according to the first embodiment. [Figure 2] This is a time chart to explain the determination made by the full charge determination unit. [Figure 3] This is a time chart illustrating the adjustment of target demand by the target demand adjustment unit. [Figure 4] This is an example flowchart illustrating the full charge percentage detection process performed by the control unit. [Figure 5] It is an example of a flowchart for explaining the target demand adjustment process performed by the control unit. [Figure 6] It is a block diagram showing the overall configuration of the charging system according to the second embodiment. [Figure 7] It is a block diagram showing the overall configuration of the charging system according to the third embodiment.

Mode for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

[0019] 〔First Embodiment〕 FIG. 1 is a block diagram showing the overall configuration of a charging system A1 according to the first embodiment. The charging system A1 is equipment for charging an electric vehicle 5. The electric vehicle 5 is an automobile equipped with an electric motor as a power source and a storage battery 54 that supplies power to the electric motor, and includes not only a so-called electric vehicle that uses only the electric motor as a power source, but also a hybrid vehicle equipped with an internal combustion engine. The charging system A1 includes a charging control device 1 and a plurality of charging devices 2.

[0020] The plurality of charging devices 2 are arranged in a parking lot or the like and charge the electric vehicle 5. In this embodiment, the charging device 2 is a so-called normal charging device, and charges the storage battery 54 of the electric vehicle 5 with single-phase AC power from a commercial power source 9. The number of charging devices 2 included in the charging system A1 is not limited. Each charging device 2 is connected to the electric vehicle 5 when a charging connector 25c arranged at the tip of a charging cable 25 is connected to a plug-in connector 55 of the electric vehicle 5. In this embodiment, the charging device 2 does not have a function of communicating with the connected electric vehicle 5. Therefore, the charging device 2 cannot detect that charging has been completed based on information from the electric vehicle 5. The charging device 2 includes a control unit 21, a communication unit 22, a power sensor 23, and an opening / closing unit 24.

[0021] The power sensor 23 is a sensor that detects the output power of the charging device 2. The power sensor 23 outputs the detected power value to the control unit 21. The control unit 21 transmits the power value input from the power sensor 23 as the output power value of the charging device 2 to the charging control device 1 via the communication unit 22.

[0022] The switching unit 24 switches the conductive path from the commercial power supply 9 to the charging cable 25 between a closed state (on) and an open state (off) in response to an opening / closing command from the control unit 21. The switching unit 24 is, for example, a relay switch, but is not limited to that.

[0023] The communication unit 22 communicates with the charging control device 1. The communication unit 22 communicates bidirectionally with the charging control device 1 via a communication line. The communication unit 22 may also communicate with the charging control device 1 via wireless communication. The communication standard is not limited. The communication unit 22 receives control commands from the charging control device 1 and outputs them to the control unit 21. The control unit 21 controls the charging of the electric vehicle 5 by outputting open / close commands to the open / close unit 24 in response to the control commands. The communication unit 22 also receives output power values ​​from the control unit 21 and transmits them to the charging control device 1. The information transmitted and received between the communication unit 22 and the charging control device 1 is not limited.

[0024] The control unit 21 controls the charging device 2 and is implemented, for example, by a microcomputer. The control unit 21 outputs an open / close command to the open / close unit 24 in response to a control command received by the communication unit 22 from the charging control device 1. The way in which the control unit 21 outputs the open / close command in response to the control command is not limited. Alternatively, the charging device 2 may be equipped with a power adjustment mechanism to adjust the output power instead of the open / close unit 24, and the control unit 21 may adjust the output power in response to the control command. The control unit 21 also transmits the power value input from the power sensor 23 to the charging control device 1 via the communication unit 22.

[0025] The charging control device 1 controls the charging of multiple charging devices 2. The charging control device 1 controls the output power of the charging system A1 based on the target demand input from the higher-level device 8.

[0026] The higher-level device 8 is responsible for energy management of the charging system A1 (each charging device 2) and other equipment (not shown) installed in the facility. This equipment includes, for example, power generation systems such as solar power generation systems, energy storage systems equipped with batteries for storing electricity, and various loads installed in the facility. The higher-level device 8 detects the total power used in the facility and controls each piece of equipment so that the demand value, which is the average power consumption over a demand period (e.g., 30 minutes), does not exceed the contracted power. The demand period is not limited to 30 minutes. The higher-level device 8 sets and outputs a target demand for each piece of equipment based on the contracted power and the demand value. Each piece of equipment controls itself so that the demand value of its output power does not exceed the set target demand. The higher-level device 8 also outputs the target demand to the charging system A1 (charging control device 1).

[0027] The charging control device 1 controls the demand value of the output power of the charging system A1 so as not to exceed the target demand input from the higher-level device 8. The charging system A1 also has a function to automatically adjust the target demand to an appropriate value. The charging control device 1 comprises a control unit 11 and a communication unit 12.

[0028] The communication unit 12 performs bidirectional communication with each charging device 2 via a communication line. Note that communication between the communication unit 12 and the communication unit 22 may be wireless communication. The communication unit 12 receives output power values ​​from each charging device 2 and outputs them to the control unit 11. The communication unit 12 also transmits the control commands output by the control unit 11 to the corresponding charging devices 2. Note that the information transmitted and received between the communication unit 12 and the communication unit 22 is not limited.

[0029] The control unit 11 is configured to control the charging control device 1 and is implemented by, for example, a microcomputer. The control unit 11 includes, as a functional configuration, a target demand acquisition unit 111, a power control unit 112, a charging demand detection unit 113, an abnormality detection unit 114, a full charge determination unit 115, a percentage detection unit 116, and a target demand adjustment unit 117.

[0030] The target demand acquisition unit 111 acquires the target demand input from the host device 8. The target demand acquired by the target demand acquisition unit 111 is stored in a storage unit (not shown). As described later, the target demand stored in the storage unit is updated to a value adjusted by the target demand adjustment unit 117 and input to the power control unit 112. Furthermore, if the target demand input from the host device 8 changes, the target demand acquisition unit 111 updates the target demand stored in the storage unit to the acquired target demand.

[0031] The power control unit 112 controls the total output power of the charging system A1 (hereinafter referred to as "total output power") based on the target demand stored in the memory unit. The power control unit 112 receives the detected power value of the total output power as input and calculates the demand value at the demand time limit (e.g., 30 minutes). In Figure 1, the total output power is detected on the power line to which all charging devices 2 are connected, but it is not limited to this, and may also be calculated by integrating the power values ​​detected by the power sensor 23 in each charging device 2. The power control unit 112 generates control commands for each charging device 2 so that the demand value of the total output power does not exceed the target demand, and transmits them via the communication unit 12. For example, the power control unit 112 suppresses the total output power by stopping charging of one of the charging devices 2. The method of generating control commands for each charging device 2 is not limited. Each charging device 2 controls itself according to the control command it receives, so that the demand value of the total output power does not exceed the target demand.

[0032] The charging demand detection unit 113 detects the demand value (hereinafter referred to as "charging demand") for each charging device 2 at a demand time limit (e.g., 30 minutes) based on the output power value of each charging device 2 received by the communication unit 12. Note that this demand time limit does not necessarily have to match the demand time limit of the higher-level device 8, and is not limited to 30 minutes.

[0033] The abnormality detection unit 114 detects the occurrence of an abnormality in each charging device 2. If an abnormality is detected, the control unit 11 stops charging the corresponding charging device 2.

[0034] The full charge determination unit 115 determines whether each charging device 2 has completed charging the connected electric vehicle 5 (storage battery 54). The full charge determination unit 115 determines that the charging device 2 has completed charging if it satisfies both the first and second conditions. In this embodiment, the first condition is that the charging demand detected by the charging demand detection unit 113 is below the determination threshold value. In this embodiment, the determination threshold value is, for example, "0" kW. Note that a small value may be set as the determination threshold value to account for detection errors. The instantaneous power value may momentarily fall below the determination threshold value even if charging is not complete. Also, the charging device 2 may temporarily stop charging due to control by the charging control device 1. In this case as well, charging is not complete, but the instantaneous power value will temporarily fall below the determination threshold value. Therefore, in the first condition, the charging demand is compared with the determination threshold value. If the charging demand is below the determination threshold value (for example, "0" kW), it can basically be determined that charging is complete.

[0035] If an abnormality occurs in the charging device 2, the control unit 11 stops charging the corresponding charging device 2 to prevent accidents and malfunctions. In this case, the output power of the charging device 2 becomes "0" kW and the charging demand also becomes "0" kW, but this does not mean that charging has been completed and stopped. To exclude cases where charging is stopped due to an abnormality, the second condition is that no abnormality is detected by the abnormality detection unit 114.

[0036] Figure 2 is a time chart illustrating the determination made by the full charge determination unit 115. In Figures 2(a), (b), and (c), the horizontal axis represents time in time blocks of 30 minutes. The upper section shows the charge demand for each time block as detected by the charge demand detection unit 113, and the lower section shows the time change in the detection results of the abnormality detection unit 114. The determination criterion value is set to "0" kW.

[0037] In the example shown in Figure 2(a), the charging demand decreases from the 3:30 time frame and becomes "0" kW from the 6:00 time frame onward. Also, the detection result of the abnormality detection unit 114 is always "normal". In this example, at the end of the 6:00 time frame (6:30), the charging device 2 satisfies both the first and second conditions, so the full charge determination unit 115 determines that the charging device 2 has completed charging.

[0038] In the example in Figure 2(b), the charging demand decreases from the 6:00 time frame, but does not fall below the judgment threshold even in the final 7:00 time frame. The detection result of the abnormality detection unit 114 is always "normal". In this example, the charging device 2 satisfies the second condition but does not satisfy the first condition, so the full charge determination unit 115 determines that the charging device 2 has not completed charging.

[0039] In the example in Figure 2(c), the charging demand decreases from the 3:30 time frame, but an anomaly occurs midway through the 4:00 time frame, and the detection result of the anomaly detection unit 114 changes to "anomaly". As a result, charging stops, and the power output is "0" kW from the 4:30 time frame onward. In this example, the charging device 2 satisfies the first condition but does not satisfy the second condition, so the full charge determination unit 115 determines that the charging device 2 has not completed charging.

[0040] The ratio detection unit 116 detects the full charge ratio, which is the percentage of charging devices 2 that have completed charging. The charging control device 1 has a charging period set according to the usage of the charging system A1. The charging period is the period during which each charging device 2 is most often used for charging. For example, if the charging system A1 is installed in an apartment building, each charging device 2 is often connected to electric vehicles 5 used by residents during the day and charged at night. In this case, the charging period is set to the nighttime hours (e.g., 22:00 to 7:00). Also, if the charging system A1 is installed in a facility and employees who come to the facility use it to charge their commuter electric vehicles 5, each charging device 2 is often charged during working hours. In this case, the charging period is set to the working hours (e.g., 8:00 to 17:00). Note that the charging period is not limited. The ratio detection unit 116 detects the full charge ratio at the end of the charging period.

[0041] The ratio detection unit 116 counts the number of charging devices 2 that have been determined to have completed charging, which is the number of charging devices 2 that have been determined to have completed charging, and the number of charging devices 2 that have been determined to have not completed charging, which is the number of charging devices 2 that have been determined to have not completed charging, based on the determination made by the full charge determination unit 115. The ratio detection unit 116 calculates the full charge ratio by dividing the number of completed charging devices by the sum of the number of completed and incomplete charging devices. In this embodiment, the full charge ratio is expressed as a percentage. If the number of incomplete charging devices is "0", the full charge ratio is 100%. The ratio detection unit 116 excludes from the calculation of the full charge ratio charging devices 2 to which the electric vehicle 5 was never connected during the charging period, and charging devices 2 to which the electric vehicle 5 was connected and charging started when there was little time left until the end of the charging period.

[0042] The target demand adjustment unit 117 updates the target demand stored in the memory unit to a value adjusted based on the full charge percentage detected by the percentage detection unit 116. The target demand adjustment unit 117 decreases the target demand by a first set value if the full charge percentage is equal to or greater than the first percentage, and increases the target demand by a second set value if the full charge percentage is less than the second percentage. The second percentage is equal to or less than the first percentage. The target demand adjustment unit 117 does not change the target demand if the full charge percentage is less than the first percentage and equal to or greater than the second percentage. In this embodiment, the case where both the first and second percentages are 100% is used as an example. However, the first and second percentages are not limited to this, and may be the same or different. For example, the first percentage may be 90% and the second percentage may be 80%. Also, in this embodiment, the first set value is, for example, 20kW, and the second set value is 10kW, which is smaller than the first set value. The second setting value is set to a smaller value than the first setting value in order to keep the target demand as low as possible. The second setting value may be the same value as the first setting value, or it may be larger than the first setting value. Furthermore, the first and second setting values ​​are not limited and may be set as appropriate based on experiments and simulations. In addition, the first and second setting values ​​are not limited to fixed values ​​and may be values ​​that change according to the original target demand (for example, XX% of the original target demand). Furthermore, the first and second setting values ​​may be values ​​that change according to the full charge percentage. For example, the target demand adjustment unit 117 can increase the second setting value as the full charge percentage decreases, thereby increasing the target demand more and increasing the full charge percentage more quickly.

[0043] In this embodiment, when the target demand adjustment unit 117 adjusts the target demand, an upper limit and a lower limit are set. When the target demand is reduced by adjustment, if the reduced target demand falls below the lower limit, the target demand is set to the lower limit. Also, when the target demand is increased by adjustment, if the increased target demand falls above the upper limit, the target demand is set to the upper limit. In this embodiment, the upper limit is set to the target demand acquired by the target demand acquisition unit 111 so that the target demand does not exceed the target demand input from the host device 8. Note that the upper and lower limits are not limited. Also, at least one of the upper and lower limits does not need to be set.

[0044] Figure 3 is a time chart illustrating the adjustment of the target demand by the target demand adjustment unit 117. In Figures 3(a), (b), and (c), the horizontal axis shows time on a daily basis. The upper section shows the full charge percentage detected by the percentage detection unit 116, and the lower section shows the target demand after adjustment by the target demand adjustment unit 117. In the example in Figure 3, the lower limit of the target demand is the lower limit value X1, and the upper limit is the target demand X0 acquired by the target demand acquisition unit 111.

[0045] In the example shown in Figure 3(a), on day 1, no adjustment is made by the target demand adjustment unit 117, and the target demand X0 acquired by the target demand acquisition unit 111 is used as is. The full charge percentage on day 1 is 100%. Therefore, on day 2, a value reduced from X0 is used as the target demand. The full charge percentage on days 2 and 3 is also 100%, and on the following day, a value further reduced from the previous day's value is used as the target demand. On day 4, the target demand has become too small, so the full charge percentage is less than 100%. Therefore, on day 5, a value increased from the previous day's value is used as the target demand. However, the full charge percentage on day 5 is also less than 100%, so on day 6, a value further increased from the previous day's value is used as the target demand. As a result, the full charge percentage on day 6 is 100%. In this way, the target demand is automatically adjusted according to the percentage of full charge from the previous day, keeping it as low as possible while ensuring that electric vehicles 5 do not suffer from insufficient charging.

[0046] In the example in Figure 3(b), the situation is the same as in Figure 3(a) until the third day. However, the full charge percentage is also 100% on the fourth and fifth days. On the following day, the target demand is similarly reduced from the previous day's value (shown as white circles and dashed lines in the figure), but it falls below the lower limit X1, so the lower limit X1 is used as the target demand for the fifth and sixth days. In this way, the target demand is adjusted so that it does not become too small.

[0047] In the example in Figure 3(c), on day 1, due to previous adjustments, a value between X0 and the lower limit X1 is used as the target demand, and the full charge rate is less than 100%. Therefore, on day 2, a value increased from the previous day's value is used as the target demand. As a result, the full charge rate on day 2 is higher than the previous day, but still less than 100%. On day 3, a value increased from the previous day's value is also used as the target demand, but the full charge rate on day 4 is still less than 100%. On day 4, the target demand is similarly increased from the previous day's value (shown as white circles and dashed lines in the figure), but it is greater than or equal to the upper limit X0, so the upper limit X0 is used as the target demand. Days 5 and 6 are similar to day 4. In this way, the target demand is adjusted so that it does not become too large.

[0048] Figure 4 is an example flowchart illustrating the full charge percentage detection process performed by the control unit 11. This full charge percentage detection process is executed after the end of the charging period.

[0049] First, charging device 2 is selected (S1). The order of selection is not limited. Next, it is determined whether or not the charging device 2 is the target for calculating the full charge percentage (S2). Specifically, the control unit 11 determines whether or not it is the target charging device 2. If it is the target (S2: YES), the charging demand D of the charging device 2 is obtained. Specifically, the full charge determination unit 115 obtains the charging demand D of the charging device 2 at the last time frame of the charging period from the charging demand detection unit 113. Next, it is determined whether or not the charging demand D is less than or equal to the judgment criterion value D0 (S4). Specifically, the full charge determination unit 115 compares the charging demand D with the judgment criterion value D0 to make the determination. If the charging demand D is less than or equal to the judgment criterion value D0 (S4: YES), it is determined whether or not an abnormality has been detected (S5). Specifically, the full charge determination unit 115 makes a determination based on the detection result of the abnormality detection unit 114. If no abnormality is detected (S5:NO), the number of completed charges is increased by "1" and the process proceeds to step S8. On the other hand, if the charge demand D is greater than the determination criterion value D0 in step S4 (S4:NO), or if an abnormality is detected in step S5 (S5:YES), the number of incomplete charges is increased by "1" and the process proceeds to step S8. Note that both the number of completed charges and the number of incomplete charges are initialized to "0" at the start of the full charge percentage detection process. Also, if the charging device 2 is not the target in step S2 (S2:NO), neither the number of completed charges nor the number of incomplete charges are increased, and the process proceeds to step S8.

[0050] Next, it is determined (S8) whether the processes in steps S2 to S7 have been performed for all charging devices 2. If there are charging devices 2 that have not yet been processed (S8: NO), the process returns to step S1, another charging device 2 is selected, and the processes in steps S2 to S7 are performed. On the other hand, if the processes have been performed for all charging devices 2 (S8: YES), the full charge percentage is calculated by the percentage detection unit 116 (S9), and the full charge percentage detection process ends. The calculated full charge percentage is used in the target demand adjustment process, which will be explained next. Note that the process shown in the flowchart of Figure 4 is just one example, and the full charge percentage detection process performed by the control unit 11 is not limited to that described above.

[0051] Figure 5 is an example flowchart illustrating the target demand adjustment process performed by the control unit 11. This target demand adjustment process is executed after the full charge percentage detection process. In this flowchart, the example is given when both the first and second percentages are set to 100%.

[0052] First, the target demand is acquired (S11). Specifically, the target demand adjustment unit 117 reads the target demand stored in the memory unit. Next, it is determined whether or not the target demand input from the host device 8 has been changed (S12). Specifically, the target demand acquisition unit 111 determines whether or not the acquired target demand has been changed. If the target demand has been changed (S12: YES), the target demand stored in the memory unit is updated with the target demand input from the host device 8, and the target demand adjustment process ends. In this case, no adjustment of the target demand according to the full charge percentage is performed, and the target demand input from the host device 8 is used.

[0053] In step S12, if the target demand has not been changed (S12: NO), the target demand adjustment unit 117 performs an adjustment. First, the full charge percentage is obtained (S13). Specifically, the target demand adjustment unit 117 obtains the full charge percentage calculated in the full charge percentage detection process after the end of the charging period. Next, it is determined whether the full charge percentage is 100% or not (S14). If the full charge percentage is 100% (S14: YES), the target demand is reduced (S15). Specifically, the target demand adjustment unit 117 reduces the target demand by the first set value. Next, it is determined whether the reduced target demand is below the lower limit (S16). If it is below the lower limit (S16: YES), the target demand stored in the memory unit is updated to the lower limit (S18), and the target demand adjustment process ends. On the other hand, if the reduced target demand is greater than the lower limit (S16:NO), the target demand stored in the memory unit is updated to the reduced target demand (S17), and the target demand adjustment process ends.

[0054] On the other hand, in step S14, if the full charge percentage is not 100% (less than 100%) (S14: NO), the target demand is increased (S19). Specifically, the target demand adjustment unit 117 increases the target demand by the second set value. Next, it is determined whether the increased target demand is equal to or greater than the upper limit (S20). If it is equal to or greater than the upper limit (S20: YES), the target demand stored in the memory unit is updated to the upper limit (S21), and the target demand adjustment process ends. On the other hand, if the increased target demand is less than the upper limit (S20: NO), the target demand stored in the memory unit is updated to the increased target demand (S17), and the target demand adjustment process ends. Note that the process shown in the flowchart of Figure 5 is just one example, and the target demand adjustment process performed by the control unit 11 is not limited to those described above.

[0055] Next, the operation and effects of the charging system A1 according to this embodiment will be described.

[0056] According to this embodiment, the full charge determination unit 115 determines whether each charging device 2 has completed charging the connected electric vehicle 5 (storage battery 54). The ratio detection unit 116 detects the full charge ratio, which is the percentage of charging devices 2 that have completed charging. The target demand adjustment unit 117 then decreases the target demand by a first set value if the full charge ratio is equal to or greater than the first ratio, and increases the target demand by a second set value if the full charge ratio is less than the second ratio, which is less than or equal to the first ratio. As a result, the charging system A1 adjusts the target demand to a small value when the full charge ratio is large, distributing power consumption and further contributing to energy management. Also, the charging system A1 adjusts the target demand to a large value when the full charge ratio is small, resolving insufficient charging of the electric vehicle 5. In this way, the charging system A1 can automatically adjust the target demand to an appropriate value.

[0057] Furthermore, according to this embodiment, both the first and second percentages are 100%. Therefore, the target demand adjustment unit 117 decreases the target demand when the full charge percentage is 100%, and increases the target demand when the full charge percentage is less than 100%. As a result, the target demand adjustment unit 117 can adjust the target demand to the smallest possible value while ensuring that the electric vehicle 5 does not suffer from insufficient charging.

[0058] Furthermore, according to this embodiment, the second setting value is smaller than the first setting value. Therefore, when increasing the target demand, the target demand adjustment unit 117 changes it more slowly than when decreasing it. As a result, the target demand is kept at the smallest possible value.

[0059] Furthermore, according to this embodiment, the target demand adjustment unit 117 has upper and lower limits set when adjusting the target demand. This prevents the target demand from becoming too large or too small. By preventing the target demand from becoming too small, the operation of the UPR (Under Power Relay) can be suppressed, and the decrease in charging efficiency due to a decrease in the charging power per unit of the charging device 2 can be suppressed. In addition, in this embodiment, the target demand X0 acquired by the target demand acquisition unit 111 is set as the upper limit. This prevents the target demand from being adjusted to a value that exceeds the target demand instructed by the higher-level device 8.

[0060] Furthermore, according to this embodiment, the charging demand detection unit 113 detects the charging demand for each charging device 2 based on the output power value of each charging device 2 received by the communication unit 12. The abnormality detection unit 114 detects the occurrence of an abnormality in each charging device 2. The full charge determination unit 115 determines that the charging device 2 has completed charging if the charging demand detected by the charging demand detection unit 113 is below the determination standard value and no abnormality is detected by the abnormality detection unit 114. This allows the full charge determination unit 115 to appropriately determine the completion of charging for each charging device 2. In addition, even if information on the charging status cannot be obtained from the electric vehicle 5 to which each charging device 2 is connected, the charging control device 1 can determine the completion of charging for each charging device 2. If each charging device 2 always charges at its rated power, the completion of charging can be estimated from the charging time. However, if the electric vehicle 5 adjusts the charging power, or if charging is stopped or suppressed by energy management, the completion of charging cannot be estimated from the charging time. Even in these cases, the full charge determination unit 115 can appropriately determine when charging of the charging device 2 is complete.

[0061] In this embodiment, the case in which the power sensor 23 provided in each charging device 2 is used has been described, but this is not the only case. A power sensor may be installed on the input or output side of each charging device 2 and used.

[0062] Furthermore, in this embodiment, a case has been described in which the full charge determination unit 115 determines the completion of charging of the charging device 2 based on the charging demand and the detection result of an abnormality, but this is not limited to this. The method for determining the completion of charging is not limited.

[0063] Furthermore, although this embodiment describes the case where each charging device 2 is a standard charging device, it is not limited to this. Each charging device 2 may also be a rapid charging device.

[0064] Furthermore, although this embodiment describes the case in which the charging device 2 charges an electric vehicle 5, it is not limited to this. The charging device 2 may also charge a mobile body other than the electric vehicle 5. Other examples of such mobile bodies include, for example, motorcycles (electric motorcycles, electric-assist bicycles), ships, airplanes and other vehicles, or unmanned mobile bodies such as automated guided vehicles and drones.

[0065] [Second Embodiment] Figure 6 is a block diagram showing the overall configuration of the charging system A2 according to the second embodiment. In Figure 6, elements that are the same as or similar to those in the first embodiment are denoted by the same reference numerals as those in the first embodiment. The charging system A2 according to this embodiment differs from the charging system A1 according to the first embodiment in the method for determining the completion of charging for each charging device 2.

[0066] Each charging device 2 according to the second embodiment can communicate with the connected electric vehicle 5. The charging cable 25 has a power line 25a and a communication line 25b. The charging device 2 also further includes a second communication unit 26. The second communication unit 26 communicates with the electric vehicle 5 via the communication line 25b. The second communication unit 26 may also communicate wirelessly with the electric vehicle 5. When the electric vehicle 5 has finished charging the battery 54, it transmits a completion signal to the second communication unit 26 indicating that charging is complete. The completion signal received by the second communication unit 26 is transmitted to the charging control device 1 via the communication unit 22.

[0067] In the second embodiment, the full charge determination unit 115 determines, based on the completion signal received by the communication unit 12, whether or not each charging device 2 has completed charging the connected electric vehicle 5 (storage battery 54). The full charge determination unit 115 determines that the charging device 2 that transmitted the completion signal has completed charging.

[0068] In this embodiment as well, the full charge determination unit 115 determines whether or not the connected electric vehicle 5 has been fully charged for each charging device 2. Then, the ratio detection unit 116 detects the full charge ratio, and the target demand adjustment unit 117 adjusts the target demand according to the full charge ratio. Therefore, the charging system A2 can automatically adjust the target demand to an appropriate value. Furthermore, since the charging system A2 has a configuration common to the charging system A1, it achieves the same effects as the charging system A1.

[0069] Alternatively, the electric vehicle 5 may transmit the SOC (State of Charge) to the charging device 2, and the full charge determination unit 115 may determine that charging is complete in the charging device 2 based on the SOC received by the communication unit 12 from the charging device 2.

[0070] [Third Embodiment] Figure 7 is a block diagram showing the overall configuration of the charging system A3 according to the third embodiment. In Figure 7, elements that are the same as or similar to those in the first embodiment are denoted by the same reference numerals as those in the first embodiment. The charging system A3 according to this embodiment differs from the charging system A1 according to the first embodiment in that it receives control indicators from a host device 8 and sets a target demand based on the control indicators.

[0071] In the third embodiment, the higher-level device 8 outputs a guidance index to each piece of equipment instead of a target demand. The guidance index is an index for controlling the power used throughout the entire facility to a target power. The higher-level device 8 detects the power used throughout the entire facility and calculates the guidance index based on the difference from the target power. The higher-level device 8 outputs a common guidance index to each piece of equipment. Each piece of equipment uses the common guidance index input from the higher-level device 8 to calculate its own target value for input and output power based on the optimization problem set for it. Then, it controls its own input and output power so that it reaches that target value. By each piece of equipment autonomously controlling its input and output power based on the guidance index, the total input and output power of the entire facility is controlled to the target power.

[0072] The control unit 11 of the charging control device 1 according to the third embodiment includes an index acquisition unit 111a and a target demand calculation unit 111b instead of a target demand acquisition unit 111. The index acquisition unit 111a acquires a guidance index input from the host device 8 and outputs the acquired guidance index to the target demand calculation unit 111b. The target demand calculation unit 111b uses the guidance index to calculate the target demand based on a pre-set optimization problem. The target demand calculation unit 111b stores the calculated target demand in a storage unit.

[0073] In this embodiment as well, the full charge determination unit 115 determines whether the charging of the connected electric vehicle 5 has been completed for each charging device 2. Then, the ratio detection unit 116 detects the full charge ratio, and the target demand adjustment unit 117 adjusts the target demand according to the full charge ratio. Therefore, the charging system A3 can automatically adjust the target demand to an appropriate value. Furthermore, the charging system A3 has the same configuration as the charging system A1 and achieves the same effect as the charging system A1. Moreover, according to this embodiment, the higher-level device 8 only calculates and transmits induction indicators without having to grasp the status of each piece of equipment, so the burden of calculation and communication is small. Since there is no need to use high-performance and expensive equipment as the higher-level device 8, the initial installation cost can be reduced. In addition, when adding or removing equipment managed by the higher-level device 8 to the facility, major modifications to the higher-level device 8 are not required. The charging system A3 can accommodate such a higher-level device 8.

[0074] In this embodiment, the case where the higher-level device 8 controls each device using an induction index has been described. Similarly, the charging control device 1 may control each charging device 2 using an induction index. That is, instead of the power control unit 112 generating control commands for each charging device 2, it calculates an induction index and transmits it to each charging device 2. The control unit 21 of each charging device 2 uses the common induction index received from the charging control device 1 to calculate a target value for charging power based on the optimization problem set for each device, and controls the device so that the charging power reaches that target value.

[0075] The charging system according to the present invention is not limited to the embodiments described above. The specific configuration of each part of the charging system according to the present invention can be modified in various ways. [Explanation of Symbols]

[0076] A1-A3: Charging system, 1: Charging control device, 111a: Indicator acquisition unit, 111b: Target demand calculation unit, 112: Power control unit, 113: Charging demand detection unit, 114: Anomaly detection unit, 115: Full charge determination unit, 116: Percentage detection unit, 117: Target demand adjustment unit, 2: Charging device, 5: Electric vehicle, 54: Storage battery, 8: Higher-level equipment

Claims

1. Multiple charging devices for charging the battery of an electric mobile body that moves by driving an electric motor with the power of the battery, A charging control device that controls the plurality of charging devices, Equipped with, The charging control device is A power control unit controls the overall output power based on the target demand, Each of the aforementioned multiple charging devices includes a full charge determination unit that determines whether or not the connected storage battery has been fully charged, A percentage detection unit that detects the full charge percentage, which is the percentage of charging devices that have completed charging, A target demand adjustment unit adjusts the target demand based on the full charge ratio, It is equipped with Charging system.

2. The target demand adjustment unit decreases the target demand when the full charge ratio is equal to or greater than the first ratio, and increases the target demand when the full charge ratio is less than the second ratio. The charging system according to claim 1.

3. The target demand adjustment unit decreases the target demand by a first set value when decreasing it, and increases the target demand by a second set value smaller than the first set value when increasing it. The charging system according to claim 2.

4. The target demand adjustment unit sets the lower limit to the target demand if the reduced target demand falls below the lower limit, and sets the upper limit to the target demand if the increased target demand falls above the upper limit. The charging system according to claim 2.

5. The charging control device is A charging demand detection unit detects the charging demand, which is the demand value of the power output by each of the aforementioned multiple charging devices at the demand time limit. An abnormality detection unit for detecting the occurrence of an abnormality in each of the aforementioned multiple charging devices, Furthermore, The full charge determination unit determines that the charging of the connected battery is complete for charging devices where the detected charging demand is below the determination threshold value and no abnormality is detected. A charging system according to any one of claims 1 to 4.

6. An indicator acquisition unit that acquires induction indicators input from a higher-level device that manages the charging control device, A target demand calculation unit calculates the target demand based on a pre-set optimization problem using the aforementioned indicators, It also has, The charging system according to claim 1.

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