Charging management system

Abstract

To provide a charging management system in which an increase of a charging stand-by time can be suppressed in a case where a plurality of electric work machines are operated.SOLUTION: A charge-state acquisition unit acquires the charge state of a power storage device from each of a plurality of electric work machines. A processing unit predicts a congestion situation of a charging device on the basis of the charge state histories of the plurality of electric work machines acquired by the charge-state acquisition unit according to a rule of performing charging when the charge state of each of the electric work machines becomes equal to or lower than a charging recommendation level at which charging should be performed, and outputs a result of the prediction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This invention is a charge management system Mu To relate to. [Background technology]

[0002] When operating electric power tools such as rechargeable electric excavators, the battery storage device installed in the power tool needs to be charged. If multiple power tools are being operated in a work area and the number of charging devices is less than the number of power tools, a waiting time for charging may occur. If the waiting time for charging is long, the efficient operation of multiple power tools will be hindered. Increasing the number of rapid chargers would shorten the waiting time for charging, but this would require a significant investment.

[0003] Patent Document 1 discloses a technology for efficiently supplying batteries to multiple electric excavators with replaceable batteries. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2018-160051 [Overview of the project] [Problems that the invention aims to solve]

[0005] When operating multiple electric excavators with interchangeable batteries, it is necessary to prepare carts for transporting batteries and multiple spare batteries. Applying this technology requires significant capital investment for operation, making it impractical for small-scale work sites. The objective of this invention is to provide a charging management system that can suppress the increase in charging waiting time when operating multiple electric work machines. Mu It is about providing. [Means for solving the problem]

[0006] According to one aspect of the present invention, A charge status acquisition unit that acquires the charge status of the energy storage device from each of the multiple electric power machines, Based on the charging status history of the multiple electric power tools acquired by the charging status acquisition unit, a rule is in place to perform charging when the charging status of the multiple electric power tools falls below the recommended charging level. This is represented by the time change in the predicted number of electric power tools that are charging or waiting to be charged. A processing unit that predicts the congestion status of charging devices and outputs the prediction results. A charging management system equipped with [this feature] is provided. [Effects of the Invention]

[0008] Based on the congestion status of charging stations, it is possible to change the charging plan to charge during times when charging stations are less busy. As a result, it becomes possible to suppress the increase in waiting times for charging. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a block diagram of a charging management system according to one embodiment, a schematic diagram of multiple electric work machines managed by the charging management system, such as an electric excavator, and a charging device. [Figure 2] Figure 2 shows a graph illustrating an example of the time-dependent change in the charging status of the battery storage devices of three electric excavators, and a graph showing the time-dependent change in the number of electric excavators that are charging or waiting for their charging devices to be charged. [Figure 3] Figure 3 is a flowchart showing the processing steps performed by the processing unit of the charging management system according to the embodiment shown in Figure 1. [Figure 4] Figure 4 is a block diagram of a charging management system according to another embodiment, a schematic diagram of multiple electric work machines managed by the charging management system, such as an electric excavator, and a charging device. [Figure 5] Figure 5 is a graph showing an example of the time-dependent change in the charge state of the power storage devices of three electric excavators. [Figure 6]FIG. 6 is a flowchart of procedures executed by the processing unit of the charging management system according to the embodiment shown in FIG. 4. [Figure 7] FIG. 7 is a flowchart showing procedures executed by the control device of each of a plurality of electric shovels. [Figure 8] FIG. 8 is a graph showing an example of the time change of the charging state of three electric shovels. [Figure 9] FIG. 9 is a block diagram of a charging management system according to another embodiment, a schematic diagram of a plurality of electric working machines, such as electric shovels, managed by the charging management system, and a charging device. MODE FOR CARRYING OUT THE INVENTION

[0010] A charging management system according to an embodiment will be described with reference to FIGS. 1 to 3. FIG. 1 is a schematic diagram of a charging management system 30 according to an embodiment, a plurality of electric working machines, such as electric shovels 10, managed by the charging management system 30, and a charging device. A plurality of electric shovels 10 are operating in the work area. The work area is, for example, an industrial waste treatment plant. For example, a transport vehicle transports industrial waste into a storage yard and unloads the industrial waste at the storage yard. The electric shovel 10 transports industrial waste from the storage yard to a crusher.

[0011] Each of the electric shovels 10 is equipped with a power storage device 11, an electric motor 12, a control device 13, and a display device 14. The electric motor 12 is driven by power from the power storage device 11 under the control of the control device 13. The display device 14 displays various information useful for the operation of the electric shovel 10 under the control of the control device 13. The control device 13 measures the state of charge (SOC) of the power storage device 11 and transmits the measurement result to the charging management system 30.

[0012] The charging device 20 rapidly charges the individual power storage devices 11 of multiple electric excavators 10. The number of power storage devices 11 is less than the number of electric excavators 10. In addition, there are standard charging facilities 25 for each electric excavator 10. The standard charging facilities 25 charge the power storage devices 11 of the electric excavators 10, for example, at night when the electric excavators 10 are not in operation. By the start of work the next day, all the power storage devices 11 of the electric excavators 10 are fully charged. The charging device 20 is used to quickly charge the power storage devices 11 if their charge level drops during working hours.

[0013] The charging management system 30 includes a charging status acquisition unit 31, a processing unit 32, and an output unit 33. The charging status acquisition unit 31 acquires the charging status of the energy storage device 11 from each of the multiple electric excavators 10 at regular intervals. Short-range wireless communication, such as Wi-Fi, can be used for data communication between the electric excavators 10 and the charging management system 30.

[0014] Based on the charging status history of the electric excavators 10, the processing unit 32 predicts the congestion status of the charging device 20 under the rule that charging will be performed when the charging status of each of the multiple electric excavators 10 falls below the recommended charging level, and outputs the prediction result to the output unit 33. A specific example of the prediction method by the processing unit 32 will be explained later with reference to Figure 2.

[0015] The output unit 33 includes a display device, a communication device, etc. The predicted congestion status of the charging device 20 is displayed as an image on the display device. Alternatively, information indicating the predicted congestion status of the charging device 20 is transmitted to an external device via the communication device.

[0016] Next, with reference to Figure 2, an example of a method for predicting the congestion status of the charging device 20 will be described. Figure 2 is a graph showing an example of the time change in the charging state of the energy storage devices 11 of three electric excavators 10, and a graph showing the time change in the number of electric excavators 10 that are being charged by the charging device 20 or waiting to be charged by the charging device 20. The horizontal axis of the two graphs represents the elapsed time since the start of operation of the electric excavators 10, the vertical axis of the upper graph represents the state of charge (SOC), and the vertical axis of the lower graph represents the number of units being charged and waiting to be charged.

[0017] The charge level of each power storage device 11 of the multiple electric excavators 10 when charging is complete (hereinafter referred to as the target charge level) is denoted as SOCH, and the charge level at which additional charging is required (hereinafter referred to as the recommended charge level) is denoted as SOCL. For example, the target charge level SOCH is set to 80%, and the recommended charge level SOCL is set to 10%. The thick solid line, thin solid line, and dashed line in the graph showing the charge status represent the charge status of the power storage devices 11 of electric excavators A, B, and C, respectively (hereinafter sometimes simply referred to as "electric excavator charge status").

[0018] In the example shown in Figure 2, the charging status is predicted under the following conditions: When the charging status of electric excavators A, B, and C drops to the recommended charging level SOCL, work is stopped and charging begins. Also, there is only one charging device 20. If the charging status of another electric excavator drops to the recommended charging level SOCL while one electric excavator is charging, the electric excavator currently charging is put into a waiting state until its charging status reaches the target charging level SOCH. Once the charging status of the electric excavator currently charging reaches the target charging level SOCH, charging of the waiting electric excavator is immediately started.

[0019] At the start of operation, the charge levels of all electric excavators A, B, and C are equal to SOCH. As electric excavators A, B, and C are operated, their charge levels gradually decrease. The charge levels are periodically acquired from electric excavators A, B, and C. The rate of decrease in charge levels depends on the workload of electric excavators A, B, and C, the operation of the air conditioning system, etc. The workload can be represented, for example, by the throttle volume setting or the motor speed. Figure 2 shows an example where electric excavator A has the largest workload and electric excavator C has the smallest workload.

[0020] Therefore, the charge level of electric excavator A drops to the recommended charge level SOCL the fastest (time t1). It is assumed that electric excavator A, whose charge level has dropped to the recommended charge level SOCL, will immediately start charging. At this point, the number of units charging or waiting to charge becomes 1, and when charging of electric excavator A begins, the charge level of electric excavator A will rise. When the charge level reaches the target charge level SOCH (time t4), charging will end.

[0021] During the charging period of electric excavator A, the charge level of electric excavator B drops to the recommended charging level SOCL (time t2). However, since there is only one charging device 20, electric excavator B cannot be charged and enters a charging waiting state. Furthermore, the charge level of electric excavator C also drops to the recommended charging level SOCL (time t3). At this point, electric excavator A is charging, and electric excavators B and C are both in a charging waiting state. In other words, the number of units charging and waiting to charge becomes three.

[0022] When electric excavator A finishes charging (time t4), work begins with electric excavator A, and as the charge level of electric excavator A begins to decrease, electric excavator B begins charging. During the charging period of electric excavator B, electric excavator C is in a waiting state for charging. When electric excavator B finishes charging (time t5), work begins with electric excavator B, and as the charge level of electric excavator B begins to decrease, electric excavator C begins charging. At this point, the number of units charging or waiting to charge becomes 1. When electric excavator C finishes charging (time t6), work begins with electric excavator C, and the charge level of electric excavator C begins to decrease. At this point, the number of units charging or waiting to charge becomes zero.

[0023] Subsequently, when the charge level of electric excavator A drops to the recommended charging level SOCL (time t7), charging of electric excavator A begins. End of work time t e Next, all electric excavators A, B, and C are shut down. After that, electric excavators A, B, and C are charged by the standard charging equipment 25 (Figure 1).

[0024] Next, with reference to Figure 3, the processing performed by the processing unit 32 (Figure 1) of the charging management system 30 will be described. Figure 3 is a flowchart showing the procedure of the processing performed by the processing unit 32 (Figure 1) of the charging management system 30.

[0025] The processing unit 32 of the charging management system 30 starts acquiring charging status information from multiple electric excavators 10 (Figure 1) (step SA1). The acquisition of charging status information is repeated at regular intervals. Subsequently, based on the charging status history of the electric excavators 10, the system predicts the future congestion status of the charging device 20 (step SA2). This prediction is made using the method described with reference to Figure 2. For example, based on the charging status history up to the present, assuming that the slope of the decrease in charging status with respect to elapsed time does not change, the system determines the time when the charging status will decrease to the recommended charging level SOCL. It is assumed that a charging request will occur when the charging status of each of the multiple electric excavators 10 reaches the recommended charging level SOCL, and the congestion status of the charging device 20 is predicted. The congestion status is represented by the time change of the predicted number of electric excavators 10 charging and waiting to charge, as shown in the lower graph of Figure 2, for example.

[0026] The processing unit 32 outputs the predicted congestion status of the charging device 20 to the output unit 33 (Figure 1) (step SA3). For example, the output unit 33 is a display device, and the processing unit 32 displays the predicted change in the number of electric excavators 10 being charged and waiting to be charged in graph form on the display device.

[0027] Steps SA2 and SA3 are repeated at regular intervals until the end of the work (Step SA4). When the end of the work is reached, the acquisition of charging status information from the electric shovel 10 is stopped (Step SA5).

[0028] Next, we will describe the excellent effects of this embodiment. In this embodiment, a manager overseeing the overall operation of multiple electric excavators 10 can view the predicted congestion status of the charging device 20 displayed on the output unit 33 and adjust the charging start times of the multiple electric excavators 10 to alleviate congestion. By adjusting the charging start times, the waiting time for each of the multiple electric excavators 10 to be charged is eliminated or shortened. As a result, the overall work efficiency of the multiple electric excavators 10 can be improved without increasing the number of expensive rapid charging devices.

[0029] Next, with reference to Figures 4 to 7, a charging management system according to another embodiment will be described. Hereafter, the configuration common to the charging management system described with reference to Figures 1 to 3 will be omitted from the description. While the charging management system described with reference to Figures 1 to 3 predicts the congestion status of the charging device 20 and displays the prediction result, the charging management system 30 according to this embodiment further proposes a charging schedule to alleviate the congestion status of the charging device 20.

[0030] Figure 4 is a block diagram of the charging management system 30 according to this embodiment, a schematic diagram of multiple electric work machines managed by the charging management system 30, such as electric excavators 10, and a charging device. In addition to a charging status acquisition unit 31, a processing unit 32, and an output unit 33, the charging management system 30 includes a charging start time recommendation unit 34. The processing unit 32 determines the charging start time (hereinafter referred to as the charging start time) for each of the multiple electric excavators 10 in order to alleviate congestion at the charging device 20. The charging start time recommendation unit 34 transmits information indicating the charging start time to each of the multiple electric excavators 10.

[0031] Each of the electric excavators 10 notifies the operator of the recommended charging start time received from the charging management system 30. For example, the control device 13 of the electric excavator 10 displays a message on the display device 14 prompting the operator to start charging at the recommended charging start time.

[0032] Next, an example of determining the recommended time to start charging will be described with reference to Figure 5. Figure 5 is a graph showing an example of the time change in the charging state of the energy storage devices 11 of three electric excavators 10. The horizontal axis represents the elapsed time since the start of operation of the electric excavators 10, and the vertical axis represents the state of charge (SOC). Similar to the graph shown in Figure 2, the thick solid line, thin solid line, and dashed line in the graph represent the charging state of electric excavators A, B, and C, respectively.

[0033] The charging start time t2 for electric excavator B is determined so that charging of electric excavator B is completed at the same time (time t3) when the charge level of electric excavator C drops to the recommended charging level SOCL. Furthermore, the charging start time t1 for electric excavator A is determined so that charging of electric excavator A is completed by the charging start time t2 for electric excavator B. In other words, for electric excavators A and B, the recommended charging start time is set so that charging begins even if the charge level has not dropped to the recommended charging level SOCL.

[0034] As soon as electric excavator A finishes charging (time t2), electric excavator B begins charging. When the charge level of electric excavator C drops to the recommended charging level SOCL (time t3), electric excavator B will have finished charging, so electric excavator C can begin charging immediately.

[0035] If a charging delay is anticipated, the recommended charging start time is determined to advance the charging start time of one of the two electric excavators 10 whose charging times are expected to overlap, in order to prevent a charging delay. In the example shown in Figure 5, the charging time of electric excavator A (shown by the thick dashed line) and the charging time of electric excavator B are expected to overlap during the period from time t7 to t8. In this case, the recommended charging start time for electric excavator A is set to time t5, by moving it forward from time t6, when the charging state of electric excavator B is expected to drop to the recommended charging level SOCL, at time t7, when the charging state of electric excavator B is expected to drop to the recommended charging level SOCL.

[0036] Figure 6 is a flowchart of the procedure executed by the processing unit 32 of the charging management system 30 according to this embodiment. The processing in steps SA1, SA2, SA4, and SA5 is the same as the processing in steps SA1, SA2, SA4, and SA5 of the flowchart shown in Figure 3. In this embodiment, the processing in step SA31 is executed instead of step SA3 (Figure 3).

[0037] In step SA31, the processing unit 32 determines the recommended time for starting charging of the multiple electric excavators 10 and notifies each of the electric excavators 10.

[0038] Figure 7 is a flowchart showing the procedures performed by each control device 13 of multiple electric excavators 10. The control device 13 starts the process of transmitting information indicating the charging status of the electric excavator 10's energy storage device 11 to the charging management system 30 (step SB1). The transmission of information indicating the charging status is repeated periodically at a fixed interval. The control device 13 determines whether or not it has received information indicating the recommended time to start charging from the charging management system 30 (step SB2). If it has not received information indicating the recommended time to start charging, it waits until it receives it.

[0039] Upon receiving information indicating the recommended time to start charging, the system notifies the operator of the recommended time to start charging (step SB3). For example, the control device 13 displays a message on the display device 14 (Figure 4) prompting the operator to start charging at the recommended time. Steps SB2 and SB3 are repeated until the end of the work period. When the end of the work period is reached, the process of transmitting information indicating the charging status to the charging management system 30 is stopped (step SB5).

[0040] Next, we will describe the excellent effects of this embodiment. In this embodiment, each operator of one of the multiple electric excavators 10 is prompted to initiate charging at the recommended charging start time, allowing them to know a charging start time that is either free or has minimal waiting time. When each of the multiple electric excavators 10 starts charging at the recommended charging start time, the overall charging waiting time is reduced, enabling efficient operation of the multiple electric excavators 10.

[0041] The charging period can be considered a break time for the operator of the electric excavator 10. Knowing the recommended time to start charging allows the operator to know how much time is left until their next break. This enables them to adjust the current work process accordingly.

[0042] Next, a charging management system according to a modified example of this embodiment will be described. In the above embodiment, when the operator of the electric excavator 10 is notified of the recommended time to start charging, the operator will revise their work so that charging begins at the notified time. However, depending on the nature of the work, the current work may not be completed by the recommended time to start charging, and the operator may want to continue the current work even after the recommended time has passed. In such cases, the operator should operate the electric excavator 10 to notify the charging management system that charging cannot be started at the recommended time.

[0043] Upon receiving this notification, the charging management system should review the overall charging schedule and re-determine the recommended charging start time. The revised recommended charging start time should then be notified to multiple electric excavators 10. This helps to mitigate the increase in waiting time for charging if a particular electric excavator 10 is unable to start charging at the recommended time.

[0044] Alternatively, operators controlling multiple electric excavators 10 may share recommended charging start times for each excavator 10 and consult with each other to determine the charging order. For example, each of the electric excavators 10 could be equipped with a function to allow operators to communicate or chat with each other. The operators can use this communication or chat function to determine the charging order.

[0045] Next, we will describe a charging management system according to another embodiment with reference to Figure 8. We will omit the explanation of components common to the charging management systems described in the embodiments with reference to Figures 4 to 7 below.

[0046] Figure 8 is a graph showing an example of the time-dependent change in the charge state of three electric excavators 10. The horizontal axis represents the elapsed time since the start of operation of the electric excavator 10, and the vertical axis represents the charge state (SOC). Similar to the graph shown in Figure 5, the thick solid line, thin solid line, and dashed line in the graph represent the charge state of electric excavators A, B, and C, respectively.

[0047] In the embodiment shown in FIG. 5, the recommended charging start time is determined so that the charging times of the three power shovels A, B, and C do not overlap. Therefore, depending on the power shovel 10, there may be a case where the predicted value of the charge state is sufficiently high at the end time t of the work. In contrast, in the embodiment shown in FIG. 8, at the end time t of the work, the recommended charging start time and the charge amount are determined so that the storage device 11 (FIG. 4) is used up until the predicted value of the charge state becomes almost the recommended charge level SOCL. e For example, if charging is performed until the charge state reaches the target charge level SOCH, when it is predicted that the charge state will not drop to the recommended charge level SOCL by the end time t of the work, charging is terminated before the charge state reaches the target charge level SOCH. The charging end time is set so as to satisfy the condition that the predicted value of the charge state drops to the recommended charge level SOCL at the end time t of the work. e For example, charging of the power shovel C is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. Similarly, for the power shovel A, charging is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. For the power shovel B, charging is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH.

[0048] For example, if charging is performed until the charge state reaches the target charge level SOCH, when it is predicted that the charge state will not drop to the recommended charge level SOCL by the end time t of the work, charging is terminated before the charge state reaches the target charge level SOCH. The charging end time is set so as to satisfy the condition that the predicted value of the charge state drops to the recommended charge level SOCL at the end time t of the work. e For example, charging of the power shovel C is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. Similarly, for the power shovel A, charging is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. For the power shovel B, charging is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. e In the embodiment shown in FIG. 5, the recommended charging start time is determined so that the charging times of the three power shovels A, B, and C do not overlap. Therefore, depending on the power shovel 10, there may be a case where the predicted value of the charge state is sufficiently high at the end time t of the work. In contrast, in the embodiment shown in FIG. 8, at the end time t of the work, the recommended charging start time and the charge amount are determined so that the storage device 11 (FIG. 4) is used up until the predicted value of the charge state becomes almost the recommended charge level SOCL.

[0049] For example, if charging is performed until the charge state reaches the target charge level SOCH, when it is predicted that the charge state will not drop to the recommended charge level SOCL by the end time t of the work, charging is terminated before the charge state reaches the target charge level SOCH. The charging end time is set so as to satisfy the condition that the predicted value of the charge state drops to the recommended charge level SOCL at the end time t of the work. 11 For example, charging of the power shovel C is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. Similarly, for the power shovel A, charging is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. For the power shovel B, charging is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. 12 For example, charging of the power shovel C is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. Similarly, for the power shovel A, charging is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. For the power shovel B, charging is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. 13 For example, charging of the power shovel C is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. Similarly, for the power shovel A, charging is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. For the power shovel B, charging is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. 14 For example, charging of the power shovel C is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. Similarly, for the power shovel A, charging is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. For the power shovel B, charging is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. 15 For example, charging of the power shovel C is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. Similarly, for the power shovel A, charging is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. For the power shovel B, charging is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. 16 For example, charging of the power shovel C is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. Similarly, for the power shovel A, charging is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH. For the power shovel B, charging is started at time t, and charging is terminated at time t before the charge state reaches the target charge level SOCH.

[0050] Next, the excellent effects of this embodiment will be described. In this embodiment, the charging time is adjusted so that the predicted value of the charge state drops to the recommended charge level SOCL at the end time t of the work. Therefore, overall, the charging time is shortened, and the operating time of the power shovel 10 can be extended. At the end time t of the work e In this embodiment, the charging time is adjusted so that the predicted value of the charge state drops to the recommended charge level SOCL at the end time t of the work. Therefore, overall, the charging time is shortened, and the operating time of the power shovel 10 can be extended. At the end time t of the work eEven if the charge level drops to the recommended charge level SOCL, by performing normal charging on the energy storage devices 11 of multiple electric excavators 10, the charge level can be raised to the target charge level SOCH by the start of work the next day.

[0051] Next, a charging management system based on a modified example of the embodiment shown in Figure 8 will be described. In the embodiment shown in Figure 8, the end time of work for multiple electric excavators 10 is t e Although they are the same, the work completion time t e These may not always be the same. For example, the work plan may specify individual end times for each of the multiple electric excavators 10. In this case, it is advisable to determine the recommended charging time for each electric excavator 10 so that its charge level drops to the recommended charging level SOCL by the end time specified in the work plan.

[0052] Next, a charging management system according to another modification of the embodiment shown in Figure 8 will be described. In the embodiment shown in Figure 8, the charging time is set so that the predicted value of the charge state decreases to approximately the recommended charging level SOCL at the scheduled end time of operation. However, it is not necessarily required that the predicted value of the charge state decreases to approximately the recommended charging level SOCL. For example, if the predicted value of the charge state at the scheduled end time of work is higher than the recommended charging level SOCL, the charging end time should be determined so that charging ends before the charge state reaches the target charging level SOCH, under the condition that the predicted value of the charge state at the scheduled end time of work remains higher than the recommended charging level SOCL. In this case, information representing the charging end time should be notified to each of the multiple electric excavators 10.

[0053] Next, a charging management system according to another embodiment will be described with reference to Figure 9. The following description will omit explanations of components common to the charging management systems described in each of the embodiments with reference to Figures 1 to 8.

[0054] Figure 9 is a block diagram of the charging management system 30 according to this embodiment, a schematic diagram of multiple electric work machines managed by the charging management system 30, such as an electric shovel 10, and a charging device. In the multiple embodiments described with reference to Figures 1 to 8, a fixed charging device 20 is used as the rapid charging device. In contrast, in this embodiment, a mobile charging device 21 is used as the rapid charging device.

[0055] Next, we will describe the excellent effects of this embodiment. In this embodiment, as in other embodiments, the recommended charging start time for each of the multiple electric excavators 10 is determined. By moving the mobile charging device 21 to near the electric excavator 10 whose next recommended charging start time is approaching, when the charge level of the electric excavator 10 drops to the recommended charging level SOCL, charging can be started immediately without having to drive the electric excavator 10 to the location of the fixed charging device. This further improves work efficiency.

[0056] The embodiments described above are illustrative, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. Similar effects and benefits from similar configurations in multiple embodiments will not be mentioned sequentially for each embodiment. Furthermore, the present invention is not limited to the embodiments described above. For example, it will be obvious to those skilled in the art that various modifications, improvements, and combinations are possible. [Explanation of symbols]

[0057] 10 Electric Excavator 11. Energy storage device 12 Electric motor 13 Control device 14 Display device 20 Charging device 21 Mobile charging device 25 Normal charging equipment 30 Charging Management Systems 31 Charging status acquisition unit 32 Processing Units 33 Output section 34. Charging start time notification section

Claims

1. A charge status acquisition unit that acquires the charge status of the energy storage device from each of the multiple electric power machines, Based on the charging status history of the multiple electric power tools acquired by the charging status acquisition unit, a processing unit predicts the congestion status of the charging device, which is represented by the time change in the predicted number of electric power tools being charged and waiting to be charged, and outputs the prediction result, under the rule that charging is performed when the charging status of the multiple electric power tools falls below the recommended charging level. A charging management system equipped with [features / equipment].

2. The charging management system according to claim 1, wherein the processing unit determines and outputs a recommended time for starting charging for each of the plurality of electric power machines so as to shorten the waiting time for each of the plurality of electric power machines to charge.

3. The charging management system according to claim 2, further comprising a charging start time notification unit that notifies each of the plurality of electric power machines of information indicating the recommended charging start time for each of the plurality of electric power machines determined by the processing unit.

4. The charging management system according to claim 3, wherein the processing unit determines the recommended charging start time taking into consideration the work plans of each of the plurality of electric work machines.

5. A charge state acquisition unit that acquires the charge state of a power storage device from each of a plurality of electric work machines, A processing unit predicts the congestion status of the charging device based on the charging status history of the multiple electric power tools acquired by the charging status acquisition unit, under the rule that charging should be performed when the charging status of the multiple electric power tools falls below the recommended charging level, and outputs the prediction result. Charging start recommended time notification unit and Equipped with, The processing unit determines the recommended charging start time for each of the multiple electric power machines so as to shorten the waiting time for each of the multiple electric power machines to charge. The charging start recommendation time notification unit notifies each of the multiple electric power machines of information indicating the charging start time for each of the multiple electric power machines determined by the processing unit, The processing unit determines the recommended charging start time, taking into consideration the work plans of each of the multiple electric work machines. The work plan includes the scheduled completion time for each of the multiple electric work machines, The processing unit starts charging from the recommended charging start time determined for each of the plurality of electric work machines, and if the predicted value of the charging state at the scheduled work end time is higher than the recommended charging level, the charging end time is determined so as to be maintained under the condition that the predicted value of the charging state at the scheduled work end time is higher than the recommended charging level, and the charging end time is terminated before the charging state reaches the target charging level, and the charging management system notifies each of the plurality of electric work machines of information representing the charging end time.

6. The charging management system according to claim 3, wherein when the processing unit receives notification from at least one of the plurality of electric work machines that it is not possible to start charging at the recommended charging start time, it reviews the recommended charging start time for each of the plurality of electric work machines and notifies the plurality of electric work machines of the revised recommended charging start time.

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