Land-based power supply system, land-based power supply method

Abstract

To avoid temporary power outages when switching from generator power to shore power in shore power supply systems.SOLUTION: A shore electric line 22 is connected to a shore grid power supply 21 and storage batteries 27. A connection connector 14 is provided onshore and connects a cable 15 of an anchored vessel 12 to connect the shore electric line 22 to a marine electric line 31 in the vessel 12. A controller 28 supplies power from the shore power line 22 to the marine electric power line 31 when the shore power line 22 and the marine electric power line 31 are connected while the vessel 12 was self-supplying power with a generator 34. In that case, power is supplied from storage batteries 27 to marine electric power line 31 after synchronizing the power of storage batteries 27 with respect to the power of generator 34.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an onshore power supply system and an onshore power supply method.

Background Art

[0002] A stationary ship can supply the necessary power within the ship by operating a generator using an internal combustion engine as a power source. However, exhaust gases such as carbon dioxide (CO2), nitrogen oxides (NO x ), sulfur oxides (SO x ), etc., and further noise become problems. Therefore, as in the quay power supply system shown in Patent Document 1, by supplying power from the onshore to a stationary ship, the operation of the generator is suppressed to improve the environment in the port area.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When supplying power from the onshore to a stationary ship, since the power of the generator is cut off and then switched to the power from the onshore, an instantaneous power outage occurs temporarily within the ship. An object of the present invention is to avoid a temporary power outage when switching from the power of the generator to the onshore power in an onshore power supply system.

Means for Solving the Problems

[0005] A shore power supply system according to one aspect of the present invention comprises a battery, a shore circuit, a control unit, and a connector. The battery is located on land. The shore circuit is connected to the shore grid power supply and the battery. The control unit controls the battery and the shore circuit. The connector is located on land and connects the shore circuit to the ship's circuit by connecting the cable of a docked ship. When the ship is self-sufficient in power using a generator, and the shore circuit and the ship's circuit are connected, and power is supplied from the shore circuit to the ship's circuit, the control unit synchronizes the power from the battery with the power from the generator before supplying power from the battery to the ship's circuit. In another aspect of the present invention, a shore power supply method is used when a docked vessel is self-sufficient in power from a generator, and the vessel's cables are connected to a shore connector, thereby connecting the shore circuit and the vessel's circuit. At this time, the power from the battery is synchronized with the power from the generator, and then power is supplied from the battery to the vessel's circuit. [Effects of the Invention]

[0006] According to the present invention, power can be supplied from the battery to the ship's electrical circuit after the power from the generator has been synchronized with the power from the battery. Therefore, a temporary power outage can be avoided when switching from power from the generator to power from land. [Brief explanation of the drawing]

[0007] [Figure 1] This is a diagram showing a land-based power supply system. [Figure 2] This is a single-line diagram showing a land-based power supply system. [Figure 3] This is a flowchart showing the onshore power supply control process. [Figure 4] This diagram shows the battery in a charging state. [Figure 5] This diagram shows a state where power is supplied solely from the battery. [Figure 6] This diagram shows the state of power being supplied from the generator. [Figure 7] This diagram shows the state when the power source has been switched to the battery. [Figure 8] It is a diagram showing the state where the generator is disconnected. [Figure 9] It is a diagram showing the state of switching to the power of the grid power source. [Figure 10] It is a diagram showing the state of supplying power only from the grid power source. [Figure 11] It is a diagram showing the state of switching to the power of the storage battery. [Figure 12] It is a diagram showing the state where the grid power source is disconnected. [Figure 13] It is a diagram showing the state of switching to the power of the generator. [Figure 14] It is a diagram showing the state where the ship's electrical circuit is disconnected. [Figure 15] It is a time chart showing the operation of the embodiment. [Figure 16] It is a diagram showing the onshore power supply system of the comparative example. [Figure 17] It is a time chart showing the operation of the comparative example.

Mode for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention will be described based on the drawings. Note that each drawing is schematic and may be different from the actual one. Further, the following embodiments illustrate devices and methods for embodying the technical idea of the present invention, and do not specify the configuration to the following. That is, the technical idea of the present invention can be variously modified within the technical scope described in the claims.

[0009] 《Embodiment》 《Configuration》 FIG. 1 is a diagram showing an onshore power supply system 11. The onshore power supply system 11 is a system provided at a mooring facility in a port for supplying power from the land to a ship 12 at anchor, and includes a container 13 and a connection connector 14 (connector). As the ship 12, passenger ships, ferries, container ships, Ro-Ro ships, car carriers, bulk carriers, tankers, etc. are envisioned. However, as long as the ship 12 can generate its own power by operating a generator using an internal combustion engine as a power source, the use and form are not limited.

[0010] The container 13 is a general transportation container standardized internationally to enable intermodal transportation. It is composed of a durable sealed steel box and contains various electrical equipment and is installed on land. The connection connector 14 is installed on land, and the cable 15 of the ship 12 is connected by a plug & socket. The connection connector 14 may be fixed or movable along the quay wall according to the type of the ship 12. Here, an example of fixing the reel 16 that sends out the cable 15 to the ship 12 is shown, but it may also be fixed on the land side.

[0011] Figure 2 is a single-line diagram showing the onshore power supply system 11. The system power supply 21 is an AC power supply supplied from the commercial distribution network owned by the power company and is connected to the connection connector 14 via the onshore circuit 22. Here, a 6.6 kV high-voltage power supply is assumed as an example. The system power supply 21 and the onshore circuit 22 are connected via a switch 23, and the disconnection and connection between the system power supply 21 and the onshore circuit 22 are switched by opening and closing the switch 23. The onshore circuit 22 and the connection connector 14 are connected via a switch 24, and the disconnection and connection between the onshore circuit 22 and the connection connector 14 are switched by opening and closing the switch 24.

[0012] In the land-based power circuit 22, a battery 27 is connected between switchgear 23 and switchgear 24, via a transformer 25 and a power converter 26 in sequence. The power converter 26 is an inverter circuit that converts power from AC to DC when charging the battery 27 and converts power from DC to AC when discharging the battery 27. The battery 27 is a rechargeable secondary battery, such as a lead-acid battery, nickel-metal hydride rechargeable battery, sodium-sulfur battery, sodium-ion battery, or lithium-ion secondary battery. The power converter 26 and the battery 27 can be considered an uninterruptible power supply (UPS).

[0013] The opening and closing of switch 23, the opening and closing of switch 24, and the charging and discharging of the storage battery 27 via the power converter 26 are controlled by the land-side controller 28 (control unit). The controller 28 is composed of, for example, a microcomputer and performs land-based power supply control processing. Switch 23, switch 24, transformer 25, power converter 26, battery 27, and controller 28 are all housed and packaged in a land-based container 13. However, considering the risk of fire, separate containers may be provided for the transformer 25 and power converter 26, and for the battery 27.

[0014] The cable 15 of the ship 12 is connected at its tip to a connector 14 and at its base to a ship circuit 31, which is an AC circuit inside the ship 12. The cable 15 and the ship circuit 31 are connected via a switch 32, and the connection and disconnection of the cable 15 and the ship circuit 31 are switched by opening and closing the switch 32. A generator 34 is connected to the ship's electrical circuit 31 via a switch 33, and the connection between the ship's electrical circuit 31 and the generator 34 is switched on and off by opening and closing the switch 33. The switch 33 and generator 34 are assumed to be multiple systems, and each generator 34 is synchronized. The generator 34 is powered by an internal combustion engine (not shown).

[0015] Load equipment 37 is connected to the ship's electrical circuit 31 via a switch 35 and a transformer 36 in sequence, and the connection between the ship's electrical circuit 31 and the load equipment 37 is switched on and off by opening and closing the switch 35. The switch 35, transformer 36, and load equipment 37 are assumed to be in multiple systems. The opening and closing of switchgear 32, switchgear 33, the operation of generator 34, and switchgear 35 are controlled by a controller 38 on the ship 12. The controller 38 is composed of, for example, a microcomputer.

[0016] Next, we will describe the onshore power supply control process performed by the controller 28. Figure 3 is a flowchart showing the onshore power supply control process. In step S101, it is determined whether or not the vessel 12 is at anchor. Whether or not the vessel 12 is at anchor is determined by detecting, for example, whether the vessel 12 has dropped anchor or is moored. If the vessel 12 is not at anchor, the process proceeds to step S102 in order to charge the battery 27. On the other hand, if the vessel 12 is at anchor, the process proceeds to step S103 because the vessel 12 may request power supply from land.

[0017] In step S102, the battery 27 is charged and the program returns to the predetermined main program. Figure 4 shows the state in which the storage battery 27 is being charged. When the ship 12 is not at anchor, the controller 28 closes switch 23 and opens switch 24 to charge the battery 27 with power from the grid power supply 21. That is, the power from the grid power supply 21 is converted from a high voltage to a low voltage by the transformer 25, and then converted from AC to DC by the power converter 26 to charge the battery 27. Before the ship 12 is at anchor, the cable 15 is wound up, switch 32 is opened, switches 33 and 35 are closed, and the generator 34 is operated to supply power to the load equipment 37. That is, the power generated by the generator 34 is converted from a high voltage to a low voltage by the transformer 36 and supplied to the load equipment 37.

[0018] In step S103, it is determined whether or not the cable 15 is connected to the connection connector 14. If the cable 15 is not connected to the connection connector 14, it is determined that the ship 12 has not requested power supply from land, and the program returns to the main program. On the other hand, if the cable 15 is connected to the connection connector 14, it is determined that the ship 12 has requested power supply from land, and the program proceeds to step S104. In step S104, it is determined whether the grid power supply 21 is functioning normally. If there is an abnormality in the grid power supply 21, such as a ground fault or short circuit, power supply from the grid power supply 21 cannot be performed, and the process proceeds to step S105. On the other hand, if the grid power supply 21 is functioning normally, power supply from the grid power supply 21 can be performed, and the process proceeds to step S106.

[0019] In step S105, power is supplied solely from the battery 27 as land power, and the program returns to the predetermined main program. Figure 5 shows the state where power is supplied only from the battery 27. Here, cable 15 is connected to connection connector 14, and in the ship's electrical circuit 31, switch 32 is closed, switch 33 is open, and switch 35 is closed. When there is an abnormality in the grid power supply 21, the controller 28 opens switch 23 and closes switch 24, supplying power to the ship's electrical circuit 31 only from the battery 27. That is, the power from the battery 27 is converted from DC to AC by the power converter 26, converted from a low voltage to a high voltage by the transformer 25, and further converted from a high voltage to a low voltage by the transformer 36 before being supplied to the load equipment 37. The process of supplying power from the battery 27 ends when the ship 12 restarts the generator 34 and becomes self-sufficient in power.

[0020] In step S106, it is determined whether the ship 12 is self-sufficient in power using the generator 34 and whether it is time to start supplying power from land. If it is time to start supplying power from land, the process proceeds to step S107. On the other hand, if it is not time to start supplying power from land, the process proceeds to step S111. In step S107, the power from the battery 27 is synchronized with the power from the generator 34. Figure 6 shows the state in which power is being supplied from the generator 34. In the ship's electrical circuit 31, power is supplied to the load equipment 37 by closing all switches 32, 33, and 35 and operating the generator 34. That is, the power generated by the generator 34 is converted from a high voltage to a low voltage by the transformer 36 and supplied to the load equipment 37. The controller 28 opens both switches 23 and 24 and synchronizes the power supplied from the battery 27 with the power of the generator 34. That is, it detects the voltage, frequency, and phase of the generator 34 from the secondary side of switch 24, and converts the power supplied from the battery 27 from DC to AC by the power converter 26, and matches the frequency and phase of the generator 34. Furthermore, it matches the voltage of the generator 34 by converting from a low voltage to a high voltage by the transformer 25.

[0021] In the following step S108, power is supplied from the battery 27 to the ship's electrical circuit 31, and the power supplied to the ship's electrical circuit 31 is switched from the power of the generator 34 to the power of the battery 27. Figure 7 shows the state when the power supply has been switched to the battery 27. The controller 28 synchronizes the power supplied from the battery 27 with the power supplied from the generator 34, then closes the switch 24, supplying power from the battery 27 to the ship's electrical circuit 31. At this time, the power converter 26 controls the power supply from the battery 27 to increase the power supplied, thereby decreasing the power supplied from the generator 34 and gradually switching the power supplied to the ship's electrical circuit 31 from the power of the generator 34 to the power of the battery 27.

[0022] Figure 8 shows the state with the generator 34 disconnected. When the power supplied by the generator 34 becomes zero, the switch 33 opens, disconnecting the generator 34 from the ship's electrical circuit 31. After the generator 34 is disconnected, the controller 28 gradually shifts the power supplied from the battery 27 from the generator 34 frequency to the self-propelled oscillation frequency using the power converter 26. In this way, the switch from power supply by the generator 34 to power supply by the battery 27 is completed. The disconnection of the generator 34 is detected by estimating it based on the power supplied from the battery 27 or by obtaining the opening / closing signal of the switch 33 from the controller 38. In the following step S109, the power supplied from the battery 27 is synchronized with the power from the grid power supply 21. Specifically, the voltage, frequency, and phase of the grid power supply 21 are detected from the primary side of the switch 23, and the power supplied from the battery 27 is converted from DC to AC by the power converter 26 and matched to the frequency and phase of the grid power supply 21. Furthermore, the voltage is matched to the voltage of the grid power supply 21 by converting the lower voltage to a higher voltage by the transformer 25.

[0023] In the following step S110, power is supplied from the grid power supply 21 to the ship's circuit 31, and the power supplied to the ship's circuit 31 is switched from the power of the storage battery 27 to the power of the grid power supply 21, and the system returns to the predetermined main program. Figure 9 shows the state when the power supply has been switched to grid power 21. The controller 28 synchronizes the power supplied from the battery 27 with the power from the grid power supply 21, and then closes the switch 23, connecting the grid power supply 21 to the land-based power supply 22 in parallel, and supplying power from the grid power supply 21 to the ship's power supply 31. At this time, the power converter 26 controls the power supply from the battery 27 to decrease the power supplied, thereby increasing the power supplied from the grid power supply 21, and gradually switching the power supplied to the ship's power supply 31 from the battery 27 to the grid power supply 21. When the power supplied from the battery 27 becomes zero, the switch from power supply from the battery 27 to power supply from the grid power supply 21 is completed. In this way, power supply from land begins.

[0024] In step S111, it is determined whether or not the power supply from land is to be stopped while power is being supplied from the grid power source 21 to the ship's power circuit 31. If it is not the time to stop the power supply from land, the process proceeds to step S112. On the other hand, if it is the time to stop the power supply from land, the process proceeds to step S113. In step S112, power is supplied only from grid power source 21 as land-based power, and the program returns to the predetermined main program. Figure 10 shows a state where power is supplied only from grid power source 21. The controller 28 supplies power to the ship's electrical circuit 31 solely from the grid power supply 21. That is, it converts the power from the grid power supply 21 from a high voltage to a low voltage using a transformer 36 and supplies it to the load equipment 37. The controller 28 also charges the battery 27 using power from the grid power supply 21. That is, it converts the power from the grid power supply 21 from a high voltage to a low voltage using a transformer 25, and then converts it from AC to DC using a power converter 26 to charge the battery 27.

[0025] In step S113, the power supplied from the battery 27 is synchronized with the power from the grid power supply 21. Specifically, the voltage, frequency, and phase of the grid power supply 21 are detected from the land circuit 22, and the power supplied from the battery 27 is converted from DC to AC by the power converter 26 and matched to the frequency and phase of the grid power supply 21. Furthermore, the voltage is matched to the voltage of the grid power supply 21 by converting the low voltage to a high voltage by the transformer 25. In the following step S114, power is supplied from the battery 27 to the ship's electrical circuit 31, and the power supplied to the ship's electrical circuit 31 is switched from power from the grid power supply 21 to power from the battery 27. Figure 11 shows the state when the power supply has been switched to the battery 27. The controller 28 synchronizes the power supplied from the battery 27 with the power from the grid power supply 21, and then supplies power from the battery 27 to the ship's electrical circuit 31. At this time, the power converter 26 controls the power supply from the battery 27 to increase the power supplied, thereby decreasing the power supplied from the grid power supply 21, and gradually switching the power supplied to the ship's electrical circuit 31 from the grid power supply 21 to the power supplied from the battery 27.

[0026] Figure 12 shows the state when the grid power supply 21 is disconnected. When the power supplied from the grid power supply 21 becomes zero, the switch 23 opens, disconnecting the grid power supply 21 from the shore circuit 22 and putting it into a disconnected state. After the grid power supply 21 is disconnected, the controller 28 gradually shifts the power supplied from the battery 27 from the generator 34 frequency to the self-propelled oscillation frequency using the power converter 26. In this way, the switch from power supply from the grid power supply 21 to power supply from the battery 27 is completed. When the grid power supply 21 is disconnected from the shore circuit 22, the ship 12 restarts the generator 34 with the switch 33 open. In the following step S115, the power supplied from the battery 27 is synchronized with the power from the generator 34. That is, the power supplied from the battery 27 is converted from DC to AC by the power converter 26 and matched to the frequency of the generator 34. Furthermore, the voltage is converted from a low voltage to a high voltage by the transformer 25 to match the voltage of the generator 34. The voltage and frequency of the generator 34 are stored in the values ​​detected in step S107 and used.

[0027] In the following step S116, power is supplied from the generator 34 to the ship's electrical circuit 31, and the power supplied to the ship's electrical circuit 31 is switched from the power of the storage battery 27 to the power of the generator 34, and the program returns to the predetermined main program. Figure 13 shows the state when the power supply has been switched to generator 34. After the power supplied from the battery 27 is synchronized with the power supplied by the generator 34, when the switch 33 is closed, the controller 28 increases the power supplied by the generator 34 by decreasing the power supplied from the battery 27 through the control of the power converter 26. In this way, the power supplied to the ship's electrical circuit 31 is gradually switched from the power of the battery 27 to the power of the generator 34. Figure 14 shows the state in which the ship's electrical circuit 31 has been disconnected. When the power supplied from the battery 27 reaches zero, the switch 24 opens, disconnecting the ship's power line 31 from the land-based power line 22. In this way, the power supply from land is stopped.

[0028] 《Operation》 Next, a series of operations of the embodiment will be described. Figure 15 is a time chart showing the operation of the embodiment. Here, the power supplied by the generator Wg, the power supplied by the battery 27 Wb, the power supplied by the grid power supply 21 Ws, and the power consumed by the load equipment 37 Wc are shown. The power consumed by the load equipment 37 Wc is assumed to be constant. First, the power Wg supplied by the generator 34 is supplied to the load equipment 37, and by time t1, the synchronization of the power Wb supplied by the battery 27 with the power Wg supplied by the generator 34 is completed. At time t1, the battery 27 is connected, and from time t1 to time t2, the power supplied to the load equipment 37 is switched from the power supplied by the generator 34 Wg to the power supplied by the battery 27 Wb. In other words, by increasing the power supplied by the battery 27 Wb, the power supplied by the generator 34 Wg is decreased. At time t2, the power supplied by the generator 34 Wg becomes zero, and the generator 34 is disconnected. Up to time t2, power is supplied according to the frequency fg of the generator 34.

[0029] From time t2 to time t3, the power Wb supplied by the battery 27 is supplied to the load equipment 37. Here, power is supplied according to the self-propelled oscillation frequency fi of the power converter 26. By time t3, the synchronization of the power Wb supplied by the battery 27 with the power Ws supplied by the grid power supply 21 is completed. At time t3, the grid power supply 21 is connected, and from time t3 to time t4, the power supplied to the load equipment 37 is switched from the power supplied by the battery 27 Wb to the power supplied by the grid power supply 21 Ws. In other words, by decreasing the power supplied by the battery 27 Wb, the power supplied by the grid power supply 21 Ws is increased. At time t4, the power supplied by the battery 27 Wb becomes zero.

[0030] From time t4 to time t5, the power Ws supplied by the grid power supply 21 is supplied to the load equipment 37. By time t5, the synchronization of the power supply Wb of the battery 27 with the power supply Ws of the grid power supply 21 is completed. From time t5 to time t6, the power supplied to the load equipment 37 is switched from the power supplied by the grid power supply 21 (Ws) to the power supplied by the battery 27 (Wb). In other words, by increasing the power supplied by the battery 27 (Wb), the power supplied by the grid power supply 21 (Ws) is decreased. At time t6, the power supplied by the grid power supply 21 (Ws) becomes zero, and the grid power supply 21 is disconnected. From time t3 to time t6, power is supplied according to the frequency fs of the grid power supply 21.

[0031] From time t6 to time t7, the power Wb supplied by the battery 27 is supplied to the load equipment 37. Here, power is supplied according to the self-propelled oscillation frequency fi of the power converter 26. By time t7, the synchronization of the power Wb supplied by the battery 27 with the power Wg supplied by the generator 34 is completed. At time t7, the generator 34 is connected, and from time t7 to time t8, the power supplied to the load equipment 37 is switched from the power supplied by the battery 27 (Wb) to the power supplied by the generator 34 (Wg). In other words, by decreasing the power supplied by the battery 27 (Wb), the power supplied by the generator 34 (Wg) is increased. At time t8, the power supplied by the battery 27 (Wb) becomes zero. From time t7 onward, power is supplied according to the frequency fg of the generator 34.

[0032] Effects and Benefits Next, the main effects and advantages of the embodiment will be described. The shore power supply system 11 comprises a battery 27, a shore circuit 22, a controller 28, and a connection connector 14. The battery 27 is located on land. The shore circuit 22 is connected to the shore grid power supply 21 and the battery 27. The controller 28 controls the battery 27 and the shore circuit 22. The connection connector 14 is located on land and connects the shore circuit 22 to the ship's circuit 31 when the cable 15 of the docked ship 12 is connected to it. When the ship 12 is self-powered by the generator 34, the controller 28 supplies power from the shore circuit 22 to the ship's circuit 31 when the shore circuit 22 and the ship's circuit 31 are connected. In this case, the power from the battery 27 is synchronized with the power from the generator 34 before power is supplied from the battery 27 to the ship's circuit 31. This makes it possible to avoid a temporary power outage when switching from the power from the generator 34 to the shore power supply.

[0033] The controller 28 increases the power of the battery 27, thereby switching the power supplied to the ship's electrical circuit 31 from the power of the generator 34 to the power of the battery 27. This allows for an easy and smooth switch. When the controller 28 switches the power supplied to the ship's electrical circuit 31 to the power of the battery 27, it synchronizes the power of the battery 27 with the power of the grid power supply 21, and then supplies power to the ship's electrical circuit 31 from both the battery 27 and the grid power supply 21. This makes it possible to avoid a temporary power outage when switching from the power of the battery 27 to the power of the grid power supply 21. The controller 28 reduces the power of the battery 27, thereby switching the power supplied to the ship's electrical circuit 31 from the battery 27 to the grid power 21. This allows for an easy and smooth switch.

[0034] The controller 28, while supplying power from the grid power supply 21 to the ship's electrical circuit 31, allows the ship 12 to generate its own power using the generator 34. In this case, the power from the battery 27 is synchronized with the power from the grid power supply 21 before power is supplied from both the grid power supply 21 and the battery 27 to the ship's electrical circuit 31. This makes it possible to avoid a temporary power outage when switching from the power from the grid power supply 21 to the power from the battery 27. The controller 28 increases the power of the battery 27, thereby switching the power supplied to the ship's electrical circuit 31 from the grid power supply 21 to the battery 27. This allows for an easy and smooth switch.

[0035] When the controller 28 switches the power supplied to the ship's electrical circuit 31 to the power of the battery 27, it synchronizes the power of the battery 27 with the power of the generator 34, and then supplies power to the ship's electrical circuit 31 from both the battery 27 and the generator 34. This prevents a temporary power outage when switching from the power of the battery 27 to the power of the generator 34. The controller 28 reduces the power of the battery 27, thereby switching the power supplied to the ship's electrical circuit 31 from the battery 27 to the generator 34. This allows for an easy and smooth switch.

[0036] The controller 28 charges the battery 27 from the grid power supply 21 before the ship 12 docks. This prepares the battery for power supply after the ship is at anchor. When there is a problem with the grid power supply 21, the controller 28 supplies power to the ship's electrical circuit 31 solely from the battery 27. This backs up the grid power supply 21 and improves the reliability of the power supply. The battery 27 is housed in container 13. This enables intermodal transport and makes it easier to install at port mooring facilities. Furthermore, not only is quality stable, but many of the packaging processes are completed at the factory, significantly reducing on-site work, shortening construction time, and suppressing cost increases.

[0037] The controller 28 controls the charging and discharging of the battery 27 via the power converter 26. This allows for arbitrary control of the charging and discharging of the battery 27, enabling a stable power supply to the load equipment 37. In this shore power supply method, while the anchored vessel 12 is generating its own power with a generator 34, the cable 15 of the vessel 12 is connected to a shore connection connector 14, thereby connecting the shore power circuit 22 and the ship power circuit 31. At this time, the power of the battery 27 is synchronized with the power of the generator 34, and then the battery 27 is connected to the shore power circuit 22, supplying power from the battery 27 to the ship power circuit 31. This makes it possible to avoid a temporary power outage when switching from the power of the generator 34 to the shore power.

[0038] Comparative Example Next, we will explain the comparative examples. Figure 16 shows a comparative example of a land-based power supply system 41. Here, the configuration is the same as the embodiment described above, except that the switch 24, transformer 25, power converter 26, and storage battery 27 are omitted, so a detailed explanation of the common parts will be omitted. Since the shore power supply system 41 does not have a battery 27, it is forced to supply power to the ship's power circuit 31 solely from the grid power supply 21.

[0039] Figure 17 is a time chart showing the operation of the comparative example. Here, the power supplied by the generator 34 Wg, the power supplied by the grid power supply 21 Ws, and the power used by the load equipment 37 Wc are shown. When switching from the power supplied by the generator 34 Wg to the power supplied by the grid power supply 21 Ws, first, from time t1 to time t2, the power supplied by the generator 34 Wg is decreased. Then, from time t3 to time t4, the power supplied by the grid power supply 21 Ws is increased, and from time t4 to time t5, the power supplied by the grid power supply 21 Ws is supplied to the load equipment 37. In this way, when switching from the power supplied by the generator 34 Wg to the power supplied by the grid power supply 21 Ws, a momentary power outage occurs in the ship 12 from time t2 to t3. Also, when switching from the power supplied by the grid power supply 21 Ws to the power supplied by the generator 34 Wg, first, from time t5 to time t6, the power supplied by the grid power supply 21 Ws is decreased. Then, from time t7 to time t8, the power supply Wg of the generator 34 is increased, and from time t8, the power supply Wg of the generator 34 is supplied to the load equipment 37. In this way, even when the power supply Ws of the grid power 21 is cut off and then switched to the power supply Wg of the generator 34, a momentary power outage occurs in the ship 12 from time t6 to t7.

[0040] Variant form In the above embodiment, a configuration was described in which a storage battery 27 is added in addition to the grid power supply 21, but the invention is not limited to this. In addition, electricity obtained from renewable energy sources such as solar power generation, wind power generation, hydroelectric power generation, biomass power generation, and geothermal power generation may be supplied to the ship's power circuit 31 or used to charge the storage battery 27. In the above embodiment, a high-voltage grid power supply 21 having an AC voltage exceeding 600V and 7,000V or less has been described, but it is not limited to this. It can also be applied to low voltage AC voltages of 600V or less, and extra-high voltage AC voltages exceeding 7,000V. In the case of extra-high voltage, the extra-high voltage receiving equipment is also housed in the container 13. In the above embodiment, a configuration in which the controller 28 is housed in the container 13 has been described, but the system is not limited to this. That is, the controller 28 may be remotely controlled from the outside via communication.

[0041] Although the above description has been made with reference to a limited number of embodiments, the scope of the rights is not limited to those embodiments, and modifications of the embodiments based on the above disclosure will be obvious to those skilled in the art. [Explanation of Symbols]

[0042] 11...Onshore power supply system, 12...Ship, 13...Container, 14...Connecting connector, 15...Cable, 16...Reel, 21...Grid power supply, 22...Onshore circuit, 23...Switch, 24...Switch, 25...Transformer, 26...Power converter, 27...Battery, 28...Controller, 31...Ship circuit, 32...Switch, 33...Switch, 34...Generator, 35...Switch, 36...Transformer, 37...Load equipment, 38...Controller, 41...Onshore power supply system

Claims

1. A battery installed on land, A land-based power grid and a land-based circuit to which the battery is connected, The storage battery and the control unit that controls the shore power line, It includes a connector installed on land, to which the cables of a moored ship are connected, thereby connecting the land-based electrical circuit and the ship-based electrical circuit inside the ship, When the ship is self-sufficient in power from its generator, and the shore circuit and the ship's circuit are connected, and power is supplied from the shore circuit to the ship's circuit, the control unit synchronizes the power of the battery with the power of the generator, and then supplies power from the battery to the ship's circuit. The control unit is characterized by increasing the power of the storage battery to switch the power supplied to the ship's electrical circuit from the power of the generator to the power of the storage battery, thereby enabling a land-based power supply system.

2. The onshore power supply system according to claim 1, characterized in that, after the control unit switches the power supplied to the ship's electrical circuit to the power of the storage battery, it synchronizes the power of the storage battery with the power of the grid power supply and then supplies power to the ship's electrical circuit from the storage battery and the grid power supply.

3. The onshore power supply system according to claim 2, characterized in that the control unit reduces the power of the storage battery to switch the power supplied to the ship's electrical circuit from the power of the storage battery to the power of the grid power supply.

4. The onshore power supply system according to any one of claims 1 to 3, characterized in that when the control unit is supplying power to the ship's circuit from the grid power supply and the ship is to be powered by the generator, the power of the storage battery is synchronized with the power of the grid power supply before supplying power to the ship's circuit from the grid power supply and the storage battery.

5. The onshore power supply system according to claim 4, characterized in that the control unit increases the power of the storage battery to switch the power supplied to the ship's electrical circuit from the grid power to the power of the storage battery.

6. The onshore power supply system according to claim 5, characterized in that, after the control unit switches the power supplied to the ship's electrical circuit to the power of the storage battery, it synchronizes the power of the storage battery with the power of the generator and then supplies power from the storage battery and the generator to the ship's electrical circuit.

7. The onshore power supply system according to claim 6, characterized in that the control unit reduces the power of the storage battery to switch the power supplied to the ship's electrical circuit from the power of the storage battery to the power of the generator.

8. The onshore power supply system according to any one of claims 1 to 7, characterized in that the control unit charges the storage battery from the grid power supply before the vessel docks.

9. The onshore power supply system according to any one of claims 1 to 8, characterized in that the control unit supplies power to the ship's electrical circuit solely from the storage battery when there is an abnormality in the grid power supply.

10. The onshore power supply system according to any one of claims 1 to 9, characterized in that the storage battery is housed in a container.

11. The onshore power supply system according to any one of claims 1 to 10, characterized in that the control unit controls the charging and discharging of the storage battery via a power converter.

12. When a docked vessel is self-sufficient in power using its generator, and the vessel's cable is connected to a land-based connector, thereby connecting the land-based circuit and the vessel's circuit, the power from the battery is synchronized with the power from the generator, the battery is connected to the land-based circuit, and power is supplied from the battery to the vessel's circuit. A land-based power supply method characterized by increasing the power of the storage battery to switch the power supplied to the ship's electrical circuit from the power of the generator to the power of the storage battery.

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