Power supply device

Abstract

To charge an on-vehicle battery mounted on a working machine.SOLUTION: The power supply device includes an input unit to which DC power is input from the storage battery, a power conversion unit that converts the DC power input to the input unit into AC power, and an output unit that outputs the AC power.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a power supply device. [Background technology]

[0002] BACKGROUND ART In the technical field related to power supply devices, a power supply device such as that disclosed in Patent Document 1 is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-055577 Summary of the Invention [Problem to be solved by the invention]

[0004] Electric work machines have on-board batteries. There is a demand for technology that can charge on-board batteries at the work site of the work machine without using a commercial power source. There is also a demand for technology that can charge on-board batteries with different characteristics.

[0005] The present disclosure has an object to charge an on-board battery mounted on a work machine. [Means for solving the problem]

[0006] According to the present disclosure, there is provided a power supply device comprising an input section to which DC power is input from a storage battery, a power conversion section to convert the DC power input to the input section into AC power, and an output section to output the AC power. [Effects of the Invention]

[0007] According to the present disclosure, an on-board battery mounted on a work machine is charged. [Brief explanation of the drawings]

[0008] [Figure 1]FIG. 1 is a diagram illustrating a storage battery management system according to the first embodiment. [Figure 2] FIG. 2 is a diagram showing the power supply device according to the first embodiment. [Figure 3] FIG. 3 is a diagram showing a power supply device according to the second embodiment. [Figure 4] FIG. 4 is a flowchart showing a control method for the power supply device according to the second embodiment. [Figure 5] FIG. 5 is a diagram showing a power supply device according to the third embodiment. [Figure 6] FIG. 6 is a flowchart showing a control method for the power supply device according to the third embodiment. [Figure 7] FIG. 7 is a flowchart showing a control method for the power supply device according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to the embodiments. The components of the embodiments described below can be combined as appropriate. In addition, some components may not be used.

[0010] <Management system> 1 is a diagram showing a management system 1 for a storage battery 2 according to an embodiment. The management system 1 manages the storage battery 2. The storage battery 2 is used to charge an on-board battery 4 mounted on a work machine 3.

[0011] The storage battery 2 is a rechargeable battery that can be used repeatedly by being charged. Examples of the storage battery 2 include a lithium ion battery and a nickel-metal hydride battery. The storage battery 2 is a portable storage battery that can be transported. The storage battery 2 is transported by a delivery vehicle 5 of a delivery company.

[0012] The work machine 3 operates at a work site 101. The work machine 3 is driven by power output from an on-board battery 4. The work machine 3 is an electric work machine. Examples of the work site 101 include an urban road construction site or an indoor demolition work site. Electric work machines do not emit exhaust gases. Electric work machines emit little heat. Electric work machines are very quiet. Therefore, the work machine 3 is suitable for urban road construction or indoor demolition work.

[0013] The on-board battery 4 is a rechargeable battery that can be used repeatedly by being charged. Examples of the on-board battery 4 include a lithium-ion battery or a nickel-metal hydride battery. The on-board battery 4 is fixed to the work machine 3. The on-board battery 4 functions as a drive source for the work machine 3.

[0014] The management system 1 includes a power supply device 6, a server 7, and an information terminal 8. The power supply device 6 is used to charge the vehicle battery 4. The server 7 includes a computer system. In the embodiment, the server 7 includes a first server 7A and a second server 7B. The information terminal 8 is carried by a user 100 of the storage battery 2. Examples of the information terminal 8 include a smartphone, a tablet terminal, or a personal computer.

[0015] The power supply device 6 and the first server 7A communicate with each other via a communication system. The first server 7A and the second server 7B communicate with each other via a communication system. The second server 7B and the information terminal 8 communicate with each other via a communication system. Examples of communication systems include the Internet, a mobile phone communication network, a satellite communication network, or a local area network (LAN).

[0016] The power supply device 6 is placed at the work site 101 of the work machine 3. The server 7 is placed in a location remote from the work site 101. The first server 7A is placed, for example, in a management facility 102 owned by a work machine manufacturer. The second server 7B is placed, for example, in a delivery facility 103 owned by a delivery company that delivers the storage battery 2.

[0017] The storage battery 2 is charged at a location remote from the work site 101. In an embodiment, the storage battery 2 is charged at a delivery facility 103. A charging device 9 for the storage battery 2 is disposed at the delivery facility 103. The storage battery 2 is charged by the charging device 9 at the delivery facility 103. Power is supplied to the charging device 9 from a commercial power source 10. The charging device 9 charges the storage battery 2 based on the power supplied from the commercial power source 10.

[0018] The storage battery 2 charged by the charging device 9 at the delivery facility 103 is delivered by the delivery vehicle 5 to the work site 101 of the work machine 3. The storage battery 2 delivered to the work site 101 is connected to the power supply device 6.

[0019] The power supply device 6 outputs power used to charge the vehicle battery 4 when the storage battery 2 is connected.

[0020] The vehicle-mounted battery 4 is charged at the work site 101. A charging device 11 for the vehicle-mounted battery 4 is arranged at the work site 101. The vehicle-mounted battery 4 is charged by the charging device 11 at the work site 101.

[0021] The power supply device 6 outputs power to the charging device 11 for the vehicle-mounted battery 4. Power is supplied from the power supply device 6 to the charging device 11. The charging device 11 charges the vehicle-mounted battery 4 based on the power supplied from the power supply device 6.

[0022] The power supply device 6 has an output device 12 and a communication device 13. The storage battery 2 delivered to the work site 101 by the delivery vehicle 5 is connected to the output device 12.

[0023] When the storage battery 2 is connected, the output device 12 outputs the electric power used to charge the on-board battery 4 mounted on the work machine 3.

[0024] The output device 12 outputs power to the charging device 11 for the in-vehicle battery 4. When connected to the charging device 11, the output device 12 supplies power to the charging device 11. When connected to the storage battery 2, the output device 12 outputs power supplied from the storage battery 2 to the charging device 11. The power output from the storage battery 2 is supplied to the in-vehicle battery 4 via the output device 12 and the charging device 11.

[0025] The storage battery 2 is used to charge the on-board battery 4. The on-board battery 4 is charged based on the power output from the storage battery 2. As the on-board battery 4 is charged, the remaining capacity of the storage battery 2 decreases. The storage battery 2 used to charge the on-board battery 4 at the work site 101 is transported to a delivery facility 103 by a delivery vehicle 5. The storage battery 2 transported to the delivery facility 103 is charged by a charging device 9 at the delivery facility 103.

[0026] The communication device 13 transmits storage battery data Da related to the storage battery 2 when the storage battery 2 is connected to the output device 12.

[0027] In the embodiment, the communicator 13 is disposed in the output device 12. The communicator 13 may also be disposed in the storage battery 2.

[0028] In the embodiment, the storage battery data Da includes at least one of the usage amount of the storage battery 2, the remaining capacity of the storage battery 2, the life of the storage battery 2, and the location of the storage battery 2.

[0029] The communicator 13 communicates with the first server 7A. The communicator 13 transmits the storage battery data Da to the first server 7A.

[0030] The first server 7A receives the storage battery data Da transmitted from the communication device 13. The first server 7A stores the storage battery data Da. The first server 7A manages the storage battery data Da.

[0031] The first server 7A communicates with the second server 7B. The first server 7A transmits storage battery data Da to the second server 7B.

[0032] The second server 7B receives the storage battery data Da transmitted from the first server 7A. The second server 7B generates required energy data Db indicating the amount of energy required to charge the in-vehicle battery 4 based on the storage battery data Da.

[0033] The second server 7B provides services to the user 100 of the storage battery 2. The second server 7B responds to requests from the user 100 of the storage battery 2.

[0034] The second server 7B generates recommendation data Dc related to the delivery of the storage battery 2 based on the required energy data Db.

[0035] The recommendation data Dc includes a recommended number of storage batteries 2 to be delivered to the power supply device 6 and a recommended date and time for delivering the storage batteries 2 to the power supply device 6.

[0036] The second server 7B communicates with the information terminal 8. The second server 7B transmits the recommended data Dc to the information terminal 8.

[0037] The information terminal 8 receives the recommended data Dc transmitted from the second server 7B. The information terminal 8 has an input device 8A and an output device 8B. The input device 8A generates input data when operated by the user 100. An example of the input device 8A is a touch panel. The input device 8A may be a computer keyboard or an audio input device. The output device 8B outputs the recommended data Dc. An example of the output device 8B is a display device such as a flat panel display. The output device 8B may be an audio output device. The user 100 can check the recommended data Dc via the output device 8B of the information terminal 8.

[0038] Based on the recommendation data Dc, the user 100 operates the input device 8A of the information terminal 8 so that the storage battery 2 charged by the charging device 9 is delivered to the power supply device 6. Based on the input data input by operating the input device 8A, the information terminal 8 generates delivery request data Dd that requests that the storage battery 2 charged by the charging device 9 be delivered to the power supply device 6. The information terminal 8 transmits the delivery request data Dd to the second server 7B.

[0039] The second server 7B receives the delivery request data Dd transmitted from the information terminal 8. Based on the delivery request data Dd, the second server 7B outputs delivery command data De that commands the storage battery 2 charged by the charging device 9 to be delivered to the power supply device 6.

[0040] An output device 14 is connected to the second server 7B. Examples of the output device 14 include a display device or an audio output device. The second server 7B outputs delivery command data De to the output device 14. An operator at the delivery facility 103 can check the delivery command data De via the output device 14. Based on the delivery command data De, the operator at the delivery facility 103 can arrange for a delivery vehicle 5 to deliver the storage battery 2 charged by the charging device 9 to the power supply device 6 at the work site 101. The storage battery 2 used to charge the on-board battery 4 at the work site 101 is collected by the driver of the delivery vehicle 5 and then transported to the delivery facility 103 by the delivery vehicle 5.

[0041] The first server 7A acquires the storage battery data Df related to the storage battery 2 located in the delivery facility 103.

[0042] In the embodiment, the storage battery data Df includes the number of deliveries of the storage battery 2. The storage battery data Df may also include required energy data Db. The storage battery data Df may also include at least one of the amount of usage of the storage battery 2, the remaining capacity of the storage battery 2, the lifespan of the storage battery 2, and the location of the storage battery 2.

[0043] The first server 7A stores the storage battery data Df. The first server 7A manages the storage battery data Df. The first server 7A transmits the storage battery data Df that has been transmitted to the second server 7B.

[0044] The second server 7B receives the storage battery data Df transmitted from the first server 7A.

[0045] <Power supply> FIG. 2 is a diagram showing a power supply device 6 according to an embodiment. In the embodiment, the power supply device 6 and the charging device 11 are each arranged at a work site 101. The charging device 11 is arranged at the work site 101 to charge the on-board battery 4 of the work machine 3. The power supply device 6 is arranged at the work site 101 to supply power to the charging device 11. The storage battery 2 is connected to an output device 12 of the power supply device 6. The charging device 11 is connected to the output device 12 of the power supply device 6. The power supply device 6 supplies power output from the storage battery 2 to the charging device 11. By being connected to the output device 12 of the power supply device 6, the charging device 11 charges the on-board battery 4 using power supplied from the storage battery 2.

[0046] The work machine 3 is an electric work machine powered by an on-board battery 4. In the embodiment, the work machine 3 is an electric shovel. The electric shovel has a lower traveling body 3B having tracks 3A, an upper rotating body 3C supported by the lower traveling body 3B, and a work implement 3D supported by the upper rotating body 3C. The electric shovel also has an electric motor, a hydraulic motor, and a hydraulic actuator. The electric motor is driven by power supplied from the on-board battery 4 mounted on the work machine 3. The hydraulic motor is driven by rotational force generated by the electric motor. The hydraulic actuator is driven by hydraulic oil supplied from the hydraulic motor. The lower traveling body 3B, upper rotating body 3C, and work implement 3D are each operated by a hydraulic actuator.

[0047] The power supply device 6 includes an output device 12, a communication device 13, and a control device 15. The output device 12 has a housing 16, an input unit 17, a power conversion unit 18, and an output unit 19.

[0048] The input unit 17 includes an input terminal 20 and an input circuit 21. The power conversion unit 18 includes a power conversion circuit 22. The output unit 19 includes an output circuit 23 and an output terminal 24.

[0049] The housing 16 accommodates an input circuit 21, a power conversion circuit 22, an output circuit 23, and the control device 15. The input terminal 20 and the output terminal 24 are disposed on the outer surface of the housing 16. The input terminal 20 and the input circuit 21 are connected by a power line 25. The input circuit 21 and the power conversion circuit 22 are connected by a power line 26. The power conversion circuit 22 and the output circuit 23 are connected by a power line 27. The output circuit 23 and the output terminal 24 are connected by a power line 28.

[0050] DC power is input from the storage battery 2 to the input unit 17. The storage battery 2 is attached to and detached from the input terminal 20. In the embodiment, the input terminal 20 is connected to the storage battery 2 via a cable 29. The cable 29 is attached to and detached from both the storage battery 2 and the input terminal 20. The input terminal 20 is connected to the input circuit 21 via a power line 25. With the storage battery 2 connected to the input terminal 20, DC power is input from the storage battery 2 to the input circuit 21 via the input terminal 20. The input circuit 21 outputs the DC power input from the storage battery 2 to the power conversion circuit 22 via a power line 26.

[0051] In the embodiment, a plurality of input terminals 20 are provided. The plurality of input terminals 20 are connected in parallel to the input circuit 21. The storage battery 2 is connected to each of the plurality of input terminals 20. DC power is input to the input circuit 21 from each of the plurality of input terminals 20. The input terminals 20 include at least a first input terminal 20A and a second input terminal 20B.

[0052] Power conversion unit 18 converts DC power input to input unit 17 into AC power. Power conversion circuit 22 includes a DC / AC converter. Power conversion circuit 22 converts DC power output from input unit 17 into AC power. Power conversion circuit 22 outputs the AC power to output circuit 23 via power line 27.

[0053] AC power is input from the power conversion unit 18 to the output unit 19. The output unit 19 outputs the AC power input from the power conversion unit 18 to the outside of the power supply device 6. The output unit 19 outputs the AC power used to charge the on-board battery 4 mounted on the work machine 3. The output unit 19 outputs the AC power to the charging device 11 for the on-board battery 4. The output terminal 24 is connected to the output circuit 23 via a power line 28. The output circuit 23 outputs the AC power input from the power conversion circuit 22 to the output terminal 24 via the power line 28.

[0054] The charging device 11 is attached to and detached from the output terminal 24. In the embodiment, the output terminal 24 is connected to the charging device 11 via a cable 30. The output unit 19 outputs the AC power input from the power conversion unit 18 to the charging device 11.

[0055] The charging device 11 charges the on-board battery 4 based on AC power input from the output unit 19. In this embodiment, the charging device 11 is connected to the work machine 3 via a cable 31. A connector 3E is provided on the work machine 3. The cable 31 is attached to and detached from the connector 3E. The connector 3E is connected to the on-board battery 4. The power output from the charging device 11 is output to the on-board battery 4 via the cable 31 and the connector 3E. The on-board battery 4 is charged by the power input from the charging device 11.

[0056] The control device 15 includes a computer system. The control device 15 is connected to the input circuit 21, the power conversion circuit 22, and the output circuit 23 via a signal line 32A. The control device 15 is also connected to the communicator 13 via a signal line 32B.

[0057] With the input unit 17 and the storage battery 2 connected, the control device 15 acquires storage battery data Da related to the storage battery 2 from the input circuit 21. By connecting the input circuit 21 and the storage battery 2 via the cable 29, the input circuit 21 can acquire the storage battery data Da from a battery management system (BMS) of the storage battery 2 via the cable 29. As described above, the storage battery data Da includes at least one of the usage amount of the storage battery 2, the remaining capacity of the storage battery 2, the lifespan of the storage battery 2, and the location of the storage battery 2. With the input unit 17 and the storage battery 2 connected, the communicator 13 transmits the storage battery data Da acquired by the control device 15 to the first server 7A.

[0058] The charging device 11 can be connected to a commercial power source 10. When connected to the commercial power source 10, the charging device 11 can charge the in-vehicle battery 4 based on AC power input from the commercial power source 10.

[0059] The charging device 11 has a noise filter circuit 33. The noise filter circuit 33 includes an LC filter and / or a capacitor. When the charging device 11 charges the vehicle battery 4 using AC power input from the commercial power source 10, the charging device 11 is provided with the noise filter circuit 33. The AC power input to the charging device 11 from the commercial power source 10 is output to the vehicle battery 4 via the noise filter circuit 33. The noise filter circuit 33 suppresses noise generation.

[0060] In the embodiment, the output circuit 23 does not have a noise filter circuit. Only one noise filter circuit is arranged in the AC power path between the power line 27, which includes the output circuit 23 and the charging device 11, and the cable 31. Since the charging device 11 is provided with the noise filter circuit 33 and the output circuit 23 is not provided with a noise filter circuit, the occurrence of LC resonance is suppressed. By suppressing the occurrence of LC resonance, the occurrence of noise is suppressed. Furthermore, the input of an overvoltage or overcurrent to the charging device 11 is suppressed.

[0061] <Effects> As described above, according to the embodiment, the charged storage battery 2 is delivered from the delivery facility 103 to the work site 101. At the work site 101, the storage battery 2 is connected to the output device 12 of the power supply device 6, and the output device 12 is connected to the charging device 11. As a result, the power output from the storage battery 2 is input to the on-board battery 4 mounted on the work machine 3 via the power supply device 6 and the charging device 11. The on-board battery 4 is efficiently charged by the storage battery 2 at the work site 101 of the work machine 3. The charging device 11 can charge the on-board battery 4 at the work site 101 of the work machine 3 without using the commercial power source 10. There is no need to take the trouble of installing a commercial power source 10 at the work site 101.

[0062] The storage battery 2 outputs DC power. The DC power output from the storage battery 2 is input to an input unit 17 and then converted into AC power by a power conversion unit 18. The AC power output from the power conversion unit 18 is input to an output unit 19. The output unit 19 outputs the AC power to a charging device 11 for the in-vehicle battery 4.

[0063] The output unit 19 can output AC power to various charging devices 11. For example, in a case where a first onboard battery 4 is installed in a first work machine 3 and a second onboard battery 4 is installed in a second work machine 3, the first charging device 11 may be provided exclusively to match the characteristics of the first onboard battery 4, and the second charging device 11 may be provided exclusively to match the characteristics of the second onboard battery 4. The power supply device 6 can output AC power to each of the first charging device 11 and the second charging device 11. The power supply device 6 can output AC power used to charge various onboard batteries 4 of the work machines 3. The power supply device 6 can output AC power used to charge onboard batteries 4 with different characteristics to the charging device 11. For example, even if the output voltage of the first onboard battery 4 and the output voltage of the second onboard battery 4 are different, the power supply device 6 can output AC power used to charge the onboard batteries 4 with different characteristics to the charging device 11 without causing the power conversion unit 18 to become complicated. The power supply device 6 can output AC power to the charging device 11 with high versatility.

[0064] The output terminal 24 is detachably attached to the charging device 11. This allows the power supply device 6 to output AC power to a variety of charging devices 11.

[0065] The power supply device 6 and charging device 11 are arranged at the work site 101. The storage batteries 2 are delivered from a delivery facility 103 to the work site 101 as needed. The storage batteries 2 are attached to and detached from the power supply device 6. An appropriate number of storage batteries 2 are delivered from the delivery facility 103 to the work site 101 at an appropriate time. The storage batteries 2 used to charge the on-board batteries 4 are transported from the work site 101 to the delivery facility 103. This prevents unnecessary storage batteries 2 from remaining at the work site 101. For example, even at a work site 101 where storage space for the storage batteries 2 is limited, the on-board batteries 4 of the work machine 3 can be charged efficiently.

[0066] The output circuit 23 and the charging device 11 are connected via a power line 28, an output terminal 24, and a cable 30. When the output circuit 23 is connected to the charging device 11 having a noise filter circuit 33, the output circuit 23 does not have a noise filter circuit, so the occurrence of LC resonance is suppressed. By suppressing the occurrence of LC resonance, the occurrence of noise is suppressed. Furthermore, the input of an overvoltage or overcurrent to the charging device 11 is suppressed.

[0067] A plurality of input terminals 20 are provided. The plurality of input terminals 20 are connected in parallel to an input circuit 21. By connecting a storage battery 2 to each of the plurality of input terminals 20, for example, a large-capacity in-vehicle battery 4 is charged.

[0068] [Second embodiment] A second embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof will be simplified or omitted.

[0069] 3 is a diagram showing a power supply device 62 according to an embodiment. As in the above-described embodiment, the power supply device 62 has an input section 17 including an input terminal 20 and an input circuit 21, a power conversion section 18 including a power conversion circuit 22, and an output section 19 including an output circuit 23 and an output terminal 24.

[0070] A plurality of input terminals 20 are provided. The plurality of input terminals 20 are connected in parallel to the input circuit 21. The storage battery 2 is connected to each of the plurality of input terminals 20.

[0071] The input terminals 20 include at least a first input terminal 20A and a second input terminal 20B. The storage battery 2 is connected to each of the first input terminal 20A and the second input terminal 20B. In the following description, the storage battery 2 connected to the first input terminal 20A will be referred to as the first storage battery 2A, and the storage battery 2 connected to the second input terminal 20B will be referred to as the second storage battery 2B.

[0072] When the first storage battery 2A is connected to the first input terminal 20A, DC power is input from the first input terminal 20A to the input circuit 21. When the second storage battery 2B is connected to the second input terminal 20B, DC power is input from the second input terminal 20B to the input circuit 21.

[0073] The input unit 17 includes a switching unit 50 that switches between inputting and not inputting DC power from the storage battery 2 to the input circuit 21 when the storage battery 2 is connected to the input terminal 20. The switching unit 50 is disposed on the power line 25 between the input terminal 20 and the input circuit 21. When the input terminal 20 and the input circuit 21 are connected by the switching unit 50, DC power is input to the input circuit 21 from the storage battery 2 connected to the input terminal 20. When the input terminal 20 and the input circuit 21 are disconnected by the switching unit 50, DC power is not input to the input circuit 21 from the storage battery 2 connected to the input terminal 20.

[0074] In the embodiment, the switching unit 50 includes a first switching unit 50A arranged on the power line 25 between the first input terminal 20A and the input circuit 21, and a second switching unit 50B arranged on the power line 25 between the second input terminal 20B and the input circuit 21. When the first switching unit 50A connects the first input terminal 20A to the input circuit 21, DC power is input to the input circuit 21 from the first storage battery 2A connected to the first input terminal 20A. When the second switching unit 50B connects the second input terminal 20B to the input circuit 21, DC power is input to the input circuit 21 from the second storage battery 2B connected to the second input terminal 20B.

[0075] The control device 15 controls the switching unit 50. The control device 15 outputs a control command to operate the switching unit 50. The control device 15 controls the switching unit 50 to switch between connecting and disconnecting the input terminal 20 and the input circuit 21. The control device 15 controls the switching unit 50 to switch between inputting and not inputting DC power from the storage battery 2 connected to the input terminal 20 to the input circuit 21.

[0076] The control device 15 monitors the remaining charge of the storage battery 2 connected to the first input terminal 20A and the remaining charge of the storage battery 2 connected to the second input terminal 20B. When the difference Δr between the remaining charge of the storage battery 2 connected to the first input terminal 20A and the remaining charge of the storage battery 2 connected to the second input terminal 20B is equal to or greater than a first threshold SH1, the control device 15 controls the switching unit 50 so that DC power is input from one storage battery 2 to the input circuit 21 and DC power is not input from the other storage battery 2 to the input circuit 21. The first threshold SH1 is a predetermined value that is stored in the control device 15.

[0077] There is a one-to-one correspondence between the remaining charge of the storage battery 2 and the output voltage of the storage battery 2. The greater the remaining charge of the storage battery 2, the higher the output voltage of the storage battery 2. The less the remaining charge of the storage battery 2, the lower the output voltage of the storage battery 2. If, for example, the first storage battery 2A connected to the first input terminal 20A has a large remaining charge and the second storage battery 2B connected to the second input terminal 20B has a small remaining charge, the difference between the output voltage of the first storage battery 2A and the output voltage of the second storage battery 2B becomes large. If the difference between the output voltage of the first storage battery 2A and the output voltage of the second storage battery 2B becomes large when both the first input terminal 20A and the second input terminal 20B are connected to the input circuit 21, a short circuit may occur.

[0078] Therefore, the control device 15 monitors the remaining charge of the first storage battery 2A connected to the first input terminal 20A and the remaining charge of the second storage battery 2B connected to the second input terminal 20B. Monitoring the remaining charge of the storage battery 2 means monitoring the output voltage of the storage battery 2. When the difference Δr between the remaining charge of the first storage battery 2A connected to the first input terminal 20A and the remaining charge of the second storage battery 2B connected to the second input terminal 20B is equal to or greater than a first threshold SH1, the control device 15 operates the switching unit 50 so that DC power is input from one of the first storage battery 2A and the second storage battery 2B to the input circuit 21 and DC power is not input from the other of the first storage battery 2A and the second storage battery 2B to the input circuit 21.

[0079] 4 is a flowchart showing a control method for a power supply device 62 according to an embodiment. A first storage battery 2A is connected to a first input terminal 20A, and a second storage battery 2B is connected to a second input terminal 20B. The control device 15 controls the first switching unit 50A to connect the first input terminal 20A to the input circuit 21, and controls the second switching unit 50B to connect the second input terminal 20B to the input circuit 21. The control device 15 monitors the remaining charge of the first storage battery 2A connected to the first input terminal 20A and the remaining charge of the second storage battery 2B connected to the second input terminal 20B (step SA1).

[0080] The control device 15 determines whether the difference Δr between the remaining capacity of the first storage battery 2A and the remaining capacity of the second storage battery 2B is equal to or greater than the first threshold value SH1 (step SA2).

[0081] In step SA2, if it is determined that the difference Δr is less than the first threshold value SH1 (step SA2: No), the control device 15 controls the switching unit 50 so that DC power is input to the input circuit 21 from each of the first storage battery 2A and the second storage battery 2B (step SA3).

[0082] If it is determined in step SA2 that the difference Δr is equal to or greater than the first threshold SH1 (step SA2: Yes), the control device 15 determines whether the remaining capacity of the first storage battery 2A is greater than the remaining capacity of the second storage battery 2B (step SA4).

[0083] If it is determined in step SA4 that the remaining charge of the first storage battery 2A is greater than the remaining charge of the second storage battery 2B (step SA4: Yes), as shown in FIG. 3, the control device 15 controls the switching unit 50 so that DC power is input from the first storage battery 2A to the input circuit 21 and DC power is not input from the second storage battery 2B to the input circuit 21 (step SA5).

[0084] If it is determined in step SA4 that the remaining charge of the second storage battery 2B is greater than the remaining charge of the first storage battery 2A (step SA4: No), the control device 15 controls the switching unit 50 so that DC power is input from the second storage battery 2B to the input circuit 21 and DC power is not input from the first storage battery 2A to the input circuit 21 (step SA6).

[0085] That is, when the difference Δr is equal to or greater than the first threshold SH1 and the remaining charge of the first storage battery 2A connected to the first input terminal 20A is greater than the remaining charge of the second storage battery 2B connected to the second input terminal 20B, the control device 15 controls the switching unit 50 so that DC power is input from the first storage battery 2A to the input circuit 21 and DC power is not input from the second storage battery 2B to the input circuit 21. When the difference Δr is equal to or greater than the first threshold SH1 and the remaining charge of the second storage battery 2B connected to the second input terminal 20B is greater than the remaining charge of the first storage battery 2A connected to the first input terminal 20A, the control device 15 controls the switching unit 50 so that DC power is input from the second storage battery 2B to the input circuit 21 and DC power is not input from the first storage battery 2A to the input circuit 21.

[0086] When the difference Δr is equal to or greater than the first threshold SH1, DC power is input to the input circuit 21 from the first storage battery 2A or the second storage battery 2B, whichever has the greater remaining capacity, and DC power is not input to the input circuit 21 from the storage battery 2 with the less remaining capacity, so the difference Δr gradually decreases. When the difference Δr becomes less than the first threshold SH1, the control device 15 controls the switching unit 50 so that DC power is input to the input circuit 21 from each of the first storage battery 2A and the second storage battery 2B.

[0087] As described above, according to the embodiment, when the difference Δr between the remaining charge of the storage battery 2 connected to the first input terminal 20A and the remaining charge of the storage battery 2 connected to the second input terminal 20B is equal to or greater than the first threshold SH1, the control device 15 controls the switching unit 50 so that DC power is input from one storage battery 2 to the input circuit 21 and DC power is not input from the other storage battery 2 to the input circuit 21. This suppresses the occurrence of a short circuit.

[0088] In the embodiment, when the difference Δr is equal to or greater than the first threshold SH1, the control device 15 controls the switching unit 50 so that DC power is input from the storage battery 2 with the greater remaining capacity out of the first storage battery 2A and the second storage battery 2B to the input circuit 21, and DC power is not input from the storage battery 2 with the less remaining capacity to the input circuit 21. Therefore, the remaining capacities of the multiple storage batteries 2 are averaged.

[0089] When the difference Δr becomes less than the first threshold SH1, the control device 15 controls the switching unit 50 so that DC power is input from each of the first storage battery 2A and the second storage battery 2B to the input circuit 21. As a result, DC power is input from each of the multiple storage batteries 2 to the input circuit 21 in a state in which the occurrence of a short circuit is suppressed.

[0090] In the second embodiment, three or more input terminals 20 may be connected in parallel to the input circuit 21. When a difference Δr between the remaining capacity of the storage battery 2 with the highest remaining capacity and the remaining capacity of the storage battery 2 with the lowest remaining capacity among the storage batteries 2 connected to each of the multiple input terminals 20 is equal to or greater than a first threshold SH1, the control device 15 can control the switching unit 50 so that DC power is input to the input circuit 21 from one of the storage batteries 2 with the highest remaining capacity and the storage battery 2 with the lowest remaining capacity, and so that DC power is not input to the input circuit 21 from the other storage battery 2. The control device 15 can also control the switching unit 50 so that DC power is input to the input circuit 21 from the storage battery 2 with the highest remaining capacity and so that DC power is not input to the input circuit 21 from the storage battery 2 with the lowest remaining capacity. When the difference Δr is less than the first threshold SH1, the control device 15 can control the switching unit 50 so that DC power is input to the input circuit 21 from each of the multiple storage batteries 2.

[0091] [Third embodiment] A third embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof will be simplified or omitted.

[0092] 5 is a diagram showing a power supply device 63 according to an embodiment. Similar to the second embodiment described above, the power supply device 63 has an input unit 17 including an input terminal 20 and an input circuit 21, a power conversion unit 18 including a power conversion circuit 22, an output unit 19 including an output circuit 23 and an output terminal 24, and a switching unit 50.

[0093] The input terminals 20 include at least a first input terminal 20A and a second input terminal 20B. The first input terminal 20A and the second input terminal 20B are connected in parallel to an input circuit 21. A first storage battery 2A is connected to the first input terminal 20A. A second storage battery 2B is connected to the second input terminal 20B. The switching unit 50 includes a first switching unit 50A arranged on a power line 25 between the first input terminal 20A and the input circuit 21, and a second switching unit 50B arranged on a power line 25 between the second input terminal 20B and the input circuit 21.

[0094] In the embodiment, the power supply device 63 has a capacitor 51 connected to the switching unit 50. The capacitor 51 is disposed in the input circuit 21. The capacitor 51 is connected to the switching unit 50 via the power line 25.

[0095] The control device 15 monitors the remaining charge of the storage batteries 2 connected to each of the multiple input terminals 20. In the embodiment, the control device 15 controls the switching unit 50 so that DC power is input to the input circuit 21 from the storage battery 2 with the lowest remaining charge among the storage batteries 2 connected to each of the multiple input terminals 20, and DC power is not input to the input circuit 21 from the other storage batteries 2.

[0096] 5, the remaining charge of the first storage battery 2A is less than the remaining charge of the second storage battery 2B. The control device 15 controls the switching unit 50 so that DC power is input from the first storage battery 2A to the input circuit 21 and so that DC power is not input from the second storage battery 2B to the input circuit 21.

[0097] 6 is a flowchart showing a control method for a power supply device 63 according to an embodiment. A first storage battery 2A is connected to a first input terminal 20A, and a second storage battery 2B is connected to a second input terminal 20B. The control device 15 controls the first switching unit 50A to connect the first input terminal 20A to the input circuit 21, and controls the second switching unit 50B to connect the second input terminal 20B to the input circuit 21. The control device 15 monitors the remaining charge of the first storage battery 2A connected to the first input terminal 20A and the remaining charge of the second storage battery 2B connected to the second input terminal 20B (step SB1).

[0098] The control device 15 determines whether the remaining capacity of the first storage battery 2A is less than the remaining capacity of the second storage battery 2B (step SB2).

[0099] In step SB2, if it is determined that the remaining charge of the first storage battery 2A is less than the remaining charge of the second storage battery 2B (step SB2: Yes), as shown in FIG. 5, the control device 15 controls the switching unit 50 so that DC power is input from the first storage battery 2A to the input circuit 21 and DC power is not input from the second storage battery 2B to the input circuit 21 (step SB3).

[0100] The remaining charge of the first storage battery 2A gradually decreases as DC power is input from the first storage battery 2A to the input circuit 21. The control device 15 determines whether the remaining charge of the first storage battery 2A has become equal to or less than the second threshold SH2 (step SB4).

[0101] The second threshold value SH2 is a predetermined value and is stored in the control device 15. The second threshold value SH2 may be zero.

[0102] In step SB4, if it is determined that the remaining charge of the first storage battery 2A is equal to or less than the second threshold SH2 (step SB4: Yes), the control device 15 controls the switching unit 50 so that DC power is input from the second storage battery 2B to the input circuit 21 (step SB5).

[0103] In addition, if it is determined in step SB4 that the remaining charge of the first storage battery 2A is not equal to or less than the second threshold SH2 (step SB4: No), the processing of step SB3 and the processing of step SB4 are repeated until it is determined that the remaining charge of the first storage battery 2A is equal to or less than the second threshold SH2.

[0104] If it is determined in step SB2 that the remaining charge of the second storage battery 2B is less than the remaining charge of the first storage battery 2A (step SB2: No), the control device 15 controls the switching unit 50 so that DC power is input from the second storage battery 2B to the input circuit 21 and DC power is not input from the first storage battery 2A to the input circuit 21 (step SB6).

[0105] The remaining charge of the second storage battery 2B gradually decreases as DC power is input from the second storage battery 2B to the input circuit 21. The control device 15 determines whether the remaining charge of the second storage battery 2B has become equal to or less than the second threshold value SH2 (step SB7).

[0106] In step SB7, if it is determined that the remaining charge of the second storage battery 2B is equal to or less than the second threshold SH2 (step SB7: Yes), the control device 15 controls the switching unit 50 so that DC power is input from the first storage battery 2A to the input circuit 21 (step SB8).

[0107] In addition, if it is determined in step SB7 that the remaining charge of the second storage battery 2B is not equal to or less than the second threshold SH2 (step SB7: No), the processing of step SB6 and the processing of step SB7 are repeated until it is determined that the remaining charge of the second storage battery 2B is equal to or less than the second threshold SH2.

[0108] As described above, according to the embodiment, the control device 15 controls the switching unit 50 so that DC power is input to the input circuit 21 from the storage battery 2 with the least remaining charge out of the first storage battery 2A and the second storage battery 2B, and DC power is not supplied to the input circuit 21 from the storage battery 2 with the most remaining charge. In other words, the control device 15 preferentially uses the storage battery 2 with the least remaining charge out of the multiple storage batteries 2. This allows the control device 15 to use up the storage battery 2 with the least remaining charge in a short period of time. By transporting the used-up storage battery 2 from the work site 101 to the delivery facility 103, it is possible to prevent the used-up storage battery 2 from remaining at the work site 101.

[0109] In the embodiment, for example, after the remaining charge of the first storage battery 2A becomes equal to or less than the second threshold SH2, the control device 15 controls the switching unit 50 so that DC power is input to the input circuit 21 from the second storage battery 2B, which has the next smallest remaining charge after the first storage battery 2A. That is, when the remaining charge of the first storage battery 2A is depleted, the control device 15 switches from input of DC power from the first storage battery 2A to input of DC power from the second storage battery 2B to the input circuit 21. This allows DC power to be continuously input to the input circuit 21.

[0110] In the embodiment, a capacitor 51 is connected to the switching unit 50. Therefore, when switching from input of DC power from the first storage battery 2A to the input circuit 21 to input of DC power from the second storage battery 2B to the input circuit 21, the power stored in the capacitor 51 prevents the occurrence of a period during which DC power is not input to the input circuit 21.

[0111] In the third embodiment, three or more input terminals 20 may be connected in parallel to the input circuit 21. In a state in which a storage battery 2 is connected to each of the three or more input terminals 20, the control device 15 can control the switching unit 50 so that DC power is input to the input circuit 21 from a first storage battery 2 having the lowest remaining charge among the storage batteries 2 connected to the multiple input terminals 20, and DC power is not input to the input circuit 21 from the other storage batteries 2. Furthermore, after the remaining charge of the first storage battery 2 becomes equal to or less than the second threshold SH2, the control device 15 can control the switching unit 50 so that DC power is input to the input circuit 21 from a second storage battery 2 having the next lowest remaining charge after the first storage battery 2, and DC power is not input to the input circuit 21 from the other storage batteries 2.

[0112] It should be noted that a capacitor 51 may be connected to the switching unit 50 of the power supply device 62 described in the second embodiment above.

[0113] [Fourth embodiment] A fourth embodiment will be described below. In the following description, the same or equivalent components as those in the above-described embodiments are denoted by the same reference numerals, and the description thereof will be simplified or omitted.

[0114] In the third embodiment described above, a storage battery 2 with a small remaining amount is used preferentially among the plurality of storage batteries 2. In the fourth embodiment, an example will be described in which a storage battery 2 with a large remaining amount is used preferentially among the plurality of storage batteries 2.

[0115] 7 is a flowchart showing a method for controlling the power supply device 63 according to this embodiment. Note that the capacitor 51 may be omitted from the power supply device 63.

[0116] The control device 15 monitors the remaining charge of the first storage battery 2A connected to the first input terminal 20A and the remaining charge of the second storage battery 2B connected to the second input terminal 20B (step SC1).

[0117] The control device 15 determines whether the remaining capacity of the first storage battery 2A is greater than the remaining capacity of the second storage battery 2B (step SC2).

[0118] If it is determined in step SC2 that the remaining charge of the first storage battery 2A is greater than the remaining charge of the second storage battery 2B (step SC2: Yes), the control device 15 controls the switching unit 50 so that DC power is input from the first storage battery 2A to the input circuit 21 and DC power is not input from the second storage battery 2B to the input circuit 21 (step SC3).

[0119] The remaining charge of the first storage battery 2A gradually decreases as DC power is input from the first storage battery 2A to the input circuit 21. The control device 15 determines whether the difference Δr between the remaining charge of the first storage battery 2A and the remaining charge of the second storage battery 2B is equal to or less than the third threshold SH3 (step SC4).

[0120] The third threshold value SH3 is a predetermined value and is stored in the control device 15. The third threshold value SH3 may be zero.

[0121] If it is determined in step SC4 that the difference Δr is less than or equal to the third threshold SH3 (step SC4: Yes), the control device 15 controls the switching unit 50 so that DC power is input to the input circuit 21 from each of the first storage battery 2A and the second storage battery 2B (step SC5).

[0122] In addition, if it is determined in step SC4 that the difference Δr is not equal to or less than the third threshold value SH3 (step SC4: No), the processing of step SC3 and the processing of step SC4 are repeated until it is determined that the difference Δr is equal to or less than the third threshold value SH3.

[0123] If it is determined in step SC2 that the remaining charge of the second storage battery 2B is greater than the remaining charge of the first storage battery 2A (step SC2: No), the control device 15 controls the switching unit 50 so that DC power is input from the second storage battery 2B to the input circuit 21 and DC power is not input from the first storage battery 2A to the input circuit 21 (step SC6).

[0124] The remaining capacity of the second storage battery 2B gradually decreases as DC power is input from the second storage battery 2B to the input circuit 21. The control device 15 determines whether the difference Δr between the remaining capacity of the first storage battery 2A and the remaining capacity of the second storage battery 2B is equal to or less than the third threshold SH3 (step SC7).

[0125] If it is determined in step SC7 that the difference Δr is less than or equal to the third threshold SH3 (step SC7: Yes), the control device 15 controls the switching unit 50 so that DC power is input to the input circuit 21 from each of the first storage battery 2A and the second storage battery 2B (step SC5).

[0126] In addition, if it is determined in step SC7 that the difference Δr is not equal to or less than the third threshold SH3 (step SC7: No), the processing of step SC6 and the processing of step SC7 are repeated until it is determined that the difference Δr is equal to or less than the third threshold SH3.

[0127] As described above, in the embodiment, when the remaining charge of the first storage battery 2A connected to the first input terminal 20A is greater than the remaining charge of the second storage battery 2B connected to the second input terminal 20B, the control device 15 controls the switching unit 50 so that DC power is input from the first storage battery 2A to the input circuit 21 and DC power is not input from the second storage battery 2B to the input circuit 21. This reduces the difference Δr between the remaining charge of the first storage battery 2A and the remaining charge of the second storage battery 2B. As described above, when the difference Δr is large, a short circuit may occur. According to the embodiment, the difference Δr is reduced, thereby suppressing the occurrence of a short circuit.

[0128] When the difference Δr between the remaining charge of the first storage battery 2A and the remaining charge of the second storage battery 2B becomes equal to or less than a third threshold SH3, the control device 15 controls the switching unit 50 so that DC power is input from each of the first storage battery 2A and the second storage battery 2B to the input circuit 21. For example, when the remaining charge of the first storage battery 2A becomes equal to the remaining charge of the second storage battery 2B, the control device 15 may control the switching unit 50 so that DC power is input from each of the first storage battery 2A and the second storage battery 2B to the input circuit 21. In this way, DC power is input from each of the multiple storage batteries 2 to the input circuit 21 while preventing a short circuit from occurring. By inputting DC power from each of the multiple storage batteries 2 to the input circuit 21, the amount of DC power input from one storage battery 2 to the input circuit 21 is reduced. This prevents the life of the storage batteries 2 from being shortened.

[0129] In the fourth embodiment, three or more input terminals 20 may be connected in parallel to the input circuit 21.

[0130] [Other embodiments] In the above-described embodiment, the work machine 3 is an electric shovel. The work machine 3 may also be an electric forklift. An electric forklift has wheels, a body supported by the wheels, a mast supported by the body, and forks supported by the mast. The electric forklift also has an electric motor, a hydraulic motor, and a hydraulic actuator. The electric motor is driven by power supplied from an on-board battery 4 mounted on the work machine 3. The hydraulic motor is driven by rotational force generated by the electric motor. The hydraulic actuator is driven by hydraulic oil supplied from the hydraulic motor. The wheels, mast, and forks are each operated by a hydraulic actuator.

[0131] In the above-described embodiment, the work machine 3 does not have to have a work implement. The work machine 3 may be, for example, an electric dump truck, which is a type of electric transport vehicle. [Explanation of symbols]

[0132] 1...management system, 2...storage battery, 2A...first storage battery, 2B...second storage battery, 3...work machine, 3A...track, 3B...undercarriage, 3C...upper rotating body, 3D...work machine, 3E...connector, 4...onboard battery, 5...delivery vehicle, 6...power supply unit, 7...server, 7A...first server, 7B...second server, 8...information terminal, 8A...input device, 8B...output device, 9...charging device, 10...commercial power supply, 11...charging device, 12...output device, 13...communication device, 14...output device, 15...control device, 16...housing, 17...input unit, 18...power conversion unit, 19...output unit, 20...input terminal, 20A...first input terminal, 20B...second input terminal, 2 1...input circuit, 22...power conversion circuit, 23...output circuit, 24...output terminal, 25...power line, 26...power line, 27...power line, 28...power line, 29...cable, 30...cable, 31...cable, 32A...signal line, 32B...signal line, 33...noise filter circuit, 50...switching unit, 50A...first switching unit, 50B...second switching unit, 51...capacitor, 62...power supply unit, 63...power supply unit, 100...user, 101...work site, 102...management facility, 103...delivery facility, Da...storage battery data, Db...required energy data, Dc...recommended data, Dd...delivery request data, De...delivery command data, Df...storage battery data.

Claims

1. an input unit to which DC power is input from a storage battery; a power conversion unit that converts the DC power input to the input unit into AC power; an output unit that outputs the AC power, power supply.

2. the output unit outputs AC power used to charge an on-board battery mounted on the work machine. The power supply device of claim 1 .

3. the output unit outputs AC power to a charging device for the vehicle battery. The power supply device according to claim 2 .

4. the output unit includes an output circuit to which AC power is input from the power conversion unit, and an output terminal connected to the output circuit and to which the charging device is attached or detached. The power supply device according to claim 3.

5. the charging device has a noise filter circuit, The output circuit does not have a noise filter circuit.

5. The power supply device according to claim 4.

6. the input unit includes an input terminal to which the storage battery is attached or detached, and an input circuit to which DC power is input from the storage battery when the storage battery is connected to the input terminal. The power supply device according to any one of claims 1 to 5.

7. The input terminal is provided in plurality, the plurality of input terminals are connected in parallel to the input circuit; 7. The power supply device according to claim 6.

8. the input unit includes a switching unit that switches between inputting and not inputting DC power from the storage battery to the input circuit in a state where the storage battery is connected to the input terminal, 8. The power supply device of claim 7.

9. and a control device that controls the switching unit so that, when a difference between a remaining charge of a storage battery with the highest remaining charge and a remaining charge of a storage battery with the lowest remaining charge among the storage batteries connected to each of the plurality of input terminals is equal to or greater than a first threshold value, DC power is input from one storage battery to the input circuit and DC power is not input from the other storage battery to the input circuit.

9. The power supply device of claim 8.

10. the control device controls the switching unit so that DC power is input to the input circuit from the storage battery with the largest remaining charge and DC power is not input to the input circuit from the storage battery with the smallest remaining charge.

10. The power supply device of claim 9.

11. When the difference becomes less than a first threshold, the control device controls the switching unit so that DC power is input from each of the plurality of storage batteries to the input circuit. The power supply device of claim 10.

12. a control device that controls the switching unit so that DC power is input to the input circuit from a first storage battery having the smallest remaining charge among the storage batteries connected to the plurality of input terminals, and DC power is not input to the input circuit from the other storage batteries; 9. The power supply device of claim 8.

13. the control device controls the switching unit so that, after the remaining charge of the first storage battery becomes equal to or less than a second threshold, DC power is input to the input circuit from a second storage battery having the second smallest remaining charge after the first storage battery, and DC power is not input to the input circuit from other storage batteries.

13. The power supply device of claim 12.

14. a capacitor connected to the switching unit; The power supply device according to any one of claims 10 to 13.

15. when a remaining charge of a first storage battery connected to a first input terminal is greater than a remaining charge of a second storage battery connected to a second input terminal, controlling the switching unit so that DC power is input from the first storage battery to the input circuit and DC power is not input from the second storage battery to the input circuit; a control device that controls the switching unit so that DC power is input from each of the first storage battery and the second storage battery to the input circuit when a difference between a remaining capacity of the first storage battery and a remaining capacity of the second storage battery becomes equal to or less than a third threshold value; 9. The power supply device of claim 8.

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