JP2023127781A - Shore power supply system, shore power supply method - Google Patents

Abstract

To level out power usage in the shore power supply system so that it does not exceed the contracted power.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 grid power supply 21 and storage batteries 27 connected to the shore electric line 22 to the marine electric line 31 when the shore electric line 22 and the marine electric line 31 are connected.SELECTED DRAWING: Figure 3

Description

The present invention relates to a land power supply system and a land power supply method.

A berthed ship can provide the necessary electricity onboard by operating a generator using an internal combustion engine as the power source, but it is possible to provide the necessary electricity within the ship by using an internal combustion engine as a power source.However, carbon dioxide (CO ₂ ), nitrogen oxides ( _NO Exhaust gases such as oxides (SO _x ) and noise pose problems. Therefore, like the quay power supply system shown in Patent Document 1, by supplying power from land to moored ships, the operation of generators is suppressed and the environment of the port area is improved.

JP2012-239365A

In a land-based power supply system that supplies power from shore to moored ships, the contracted power is determined based on the load equipment capacity and load factor on board the ship. There is a possibility that the amount of electricity exceeds the contracted power.
An object of the present invention is to level out the power consumption in a land power supply system so that the power consumption does not exceed the contracted power.

A land power supply system according to one aspect of the present invention includes a storage battery, a land power line, a control unit, and a connector. The storage battery is installed on land. The land power line is connected to a land power system and a storage battery. The control unit controls the storage battery and the land power line. The connector is provided on land and connects the cable of a berthed ship to connect the land power line and the ship power line within the ship. The control unit supplies power to the marine electrical line from a system power supply and a storage battery connected to the shore electrical circuit when the onshore electrical line and the marine electrical line are connected.
In the land power supply method according to another aspect of the present invention, when the land power line and the ship power line are connected by connecting the cable of the anchored ship to the land connector, Power is supplied to the ship's electrical circuit from the grid power supply and storage battery.

According to the present invention, power is supplied to the ship's electrical circuit not only from the grid power source but also from the storage battery, so that even if the power demand on the ship temporarily increases, the power used is leveled so that it does not exceed the contracted power. It is possible to aim for

FIG. 1 is a diagram showing a land-based power supply system. FIG. 1 is a single line diagram showing a shore power supply system. It is a flowchart which shows land power supply control processing. It is a figure showing the state where a storage battery is being charged. FIG. 3 is a diagram showing a state in which power is supplied only from a storage battery. FIG. 3 is a diagram showing a state in which power is supplied only from a grid power source. FIG. 3 is a diagram showing a state in which power is supplied from a grid power source and a storage battery is being charged. FIG. 2 is a diagram showing a state in which power is supplied from both a grid power source and a storage battery. 5 is a time chart showing the operation of the embodiment. FIG. 3 is a diagram showing a land power supply system of a comparative example. 7 is a time chart showing the operation of a comparative example.

Embodiments of the present invention will be described below based on the drawings. Note that each drawing is schematic and may differ from the actual drawing. Furthermore, the following embodiments are intended to exemplify devices and methods for embodying the technical idea of the present invention, and the configuration is not limited to the following. That is, the technical idea of the present invention can be modified in various ways within the technical scope described in the claims.

《Embodiment》
"composition"
FIG. 1 is a diagram showing a land power supply system 11. As shown in FIG.
The land power supply system 11 is a system that is installed at a mooring facility in a port and supplies power from land to a moored ship 12, and includes a container 13 and a connector 14 (connector). There is.
The ships 12 are assumed to be passenger ships, ferries, container ships, Ro-Ro ships, car carriers, bulkers, tankers, etc., but ships that are self-sufficient in electricity by using an internal combustion engine as the power source and operating a generator. As long as it is 12, the purpose and form do not matter.

Container 13 is a general shipping container that has been internationally standardized to enable intermodal transportation, and is composed of a durable sealed steel box that houses various electrical equipment and is installed on land. It is being
The connector 14 is provided on land, and is connected to the cable 15 of the ship 12 using a plug and socket. The connector 14 may be of a fixed type or may be of a movable type that can be moved along the quay wall of the pier depending on the type of ship 12. Here, an example is shown in which the reel 16 for sending out the cable 15 is fixed to the ship 12, but it may be fixed to the land side.

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

A storage battery 27 is connected between the switch 23 and the switch 24 in the land power line 22 via a transformer 25 and a power converter 26 in this order. The power converter 26 is an inverter circuit, and converts power from alternating current to direct current when charging the storage battery 27, and converts power from direct current to alternating current when discharging the storage battery 27. The storage battery 27 is a secondary battery that can be charged and discharged, and is, for example, a lead-acid battery, a nickel-hydrogen rechargeable battery, a sodium-sulfur battery, a sodium ion battery, a lithium ion secondary battery, or the like. The power converter 26 and the storage battery 27 can be considered as an uninterruptible power supply (UPS).

Opening and closing of the switch 23, opening and closing of the switch 24, and charging and discharging of the storage battery 27 via the power converter 26 are controlled by a controller 28 (control unit) on the land side. The controller 28 is composed of, for example, a microcomputer, and executes land power supply control processing.
The switch 23, the switch 24, the transformer 25, the power converter 26, the storage battery 27, and the controller 28 are all housed in the container 13 on land and packaged. Note that, considering the risk of fire, a container housing the transformer 25 and the power converter 26 and a container housing the storage battery 27 may be provided separately.

The cable 15 of the ship 12 has its distal end connected to the connector 14 and its proximal end connected to a ship electrical circuit 31 that is an AC circuit inside the ship 12 . The cable 15 and the marine power line 31 are connected via a switch 32, and the disconnection and connection of the cable 15 and the marine power line 31 are switched by opening and closing the switch 32.
A generator 34 is connected to the marine power line 31 via a switch 33, and the disconnection and connection between the marine power line 31 and the generator 34 are switched by opening and closing the switch 33. It is assumed that the switch 33 and the generator 34 have a plurality of systems, and each generator 34 is synchronized. The generator 34 is operated using an internal combustion engine (not shown) as a power source.

A load equipment 37 is connected to the ship electric line 31 via a switch 35 and a transformer 36 in this order, and disconnection and connection between the ship electric line 31 and the load equipment 37 are switched by opening and closing the switch 35. It is assumed that there are multiple systems of the switch 35, the transformer 36, and the load equipment 37.
The opening and closing of the switch 32, the opening and closing of the switch 33, the operation of the generator 34, and the opening and closing of the switch 35 are controlled by a controller 38 on the ship 12 side. The controller 38 is composed of, for example, a microcomputer.

Next, the shore power supply control process executed by the controller 28 will be described.
FIG. 3 is a flowchart showing the shore power supply control process.
In step S101, it is determined whether the ship 12 is at anchor. Whether or not the ship 12 is at anchor is determined, for example, by detecting that the ship 12 is anchored or moored. When the ship 12 is not at anchor, the process moves to step S102 to charge the storage battery 27. On the other hand, when the ship 12 is at anchor, there is a possibility that the ship 12 requests power supply from land, so the process moves to step S103.

In step S102, the storage battery 27 is charged and the process returns to the predetermined main program.
FIG. 4 is a diagram showing a state in which the storage battery 27 is being charged.
The controller 28 closes the switch 23 and opens the switch 24 when the ship 12 is not at anchor, and charges the storage battery 27 with the power from the system power supply 21. That is, the electric power of the system power supply 21 is converted from a high voltage to a low voltage by the transformer 25, and from AC to DC by the power converter 26, and the storage battery 27 is charged. In addition, in the ship 12 before berthing, power is supplied to the load equipment 37 by winding the cable 15, opening the switch 32, closing the switch 33 and the switch 35, and operating the generator 34. ing. That is, the electric power generated by the generator 34 is converted from a high voltage to a low voltage by the transformer 36 and is supplied to the load equipment 37.

In step S103, it is determined whether the cable 15 is connected to the connection connector 14. When the cable 15 is not connected to the connector 14, it is determined that the ship 12 does not request power supply from land, and the process returns to the predetermined main program. On the other hand, when the cable 15 is connected to the connector 14, it is determined that the ship 12 requests power supply from land, and the process moves to step S106.
In step S104, it is determined whether the system power supply 21 is normal. When there is an abnormality such as a ground fault or a short circuit in the system power supply 21, power supply from the system power supply 21 cannot be executed, so the process moves to step S105. On the other hand, when the system power supply 21 is normal, power can be supplied from the system power supply 21, so the process moves to step S106.

In step S105, power is supplied only from the storage battery 27 as shore power, and the process returns to the predetermined main program.
FIG. 5 is a diagram showing a state in which power is supplied only from the storage battery 27.
Here, the cable 15 is connected to the connector 14, and in the ship electrical line 31, the switch 32 is closed, the switch 33 is open, and the switch 35 is closed. When there is an abnormality in the system power supply 21, the controller 28 opens the switch 23, closes the switch 24, and supplies power to the marine power line 31 only from the storage battery 27. That is, the power in the storage battery 27 is converted from DC to AC by the power converter 26, from a low voltage to a high voltage by the transformer 25, and from a high voltage to a low voltage by the transformer 36. is supplied to. The process of supplying power from the storage battery 27 ends when the ship 12 restarts the generator 34 and becomes self-sufficient in power.

In step S106, a predetermined threshold value W1 (first threshold value) is provided, and it is determined whether the power consumption Wc of the ship 12 is less than the threshold value W1. The threshold value W1 is a value that is less than the contract power Wd, and is, for example, a value that is reduced from the contract power Wd by a predetermined amount that is a margin. The contract power Wd is determined based on the load equipment capacity and load factor within the ship 12. When the power usage Wc of the ship 12 is less than the threshold value W1, it is determined that there is no possibility of exceeding the contract power Wd, and the process moves to step S107. On the other hand, when the power consumption Wc of the ship 12 is equal to or greater than the threshold value W1, it is determined that there is a possibility of exceeding the contract power Wd, and the process moves to step S110.

In step S107, power is supplied only from the grid power supply 21 as shore power, and the process returns to the predetermined main program.
FIG. 6 is a diagram showing a state in which power is supplied only from the system power supply 21.
Here, the cable 15 is connected to the connector 14, and in the ship electrical line 31, the switch 32 is closed, the switch 33 is open, and the switch 35 is closed. The controller 28 closes the switch 23 and the switch 24 when the power consumption Wc is less than the threshold value W1, and supplies power to the marine power line 31 only from the system power supply 21. That is, the electric power of the system power supply 21 is converted from a high voltage to a low voltage by the transformer 36 and is supplied to the load equipment 37.

In step S108, a predetermined threshold value W2 (second threshold value) is provided, and it is determined whether the power consumption Wc of the ship 12 is less than the threshold value W2. The threshold value W2 is a value less than the threshold value W1, and is, for example, a value reduced from the threshold value W1 by the amount of electric power required to charge the storage battery 27. The amount of power required to charge the storage battery 27 may be a fixed value or may be variable depending on the state of charge (SOC) of the storage battery 27. When the power consumption Wc of the ship 12 is less than the threshold value W2, the process moves to step S109 to charge the storage battery 27. On the other hand, when the power consumption Wc of the ship 12 is equal to or greater than the threshold value W2, in order to avoid charging the storage battery 27, the process returns to the predetermined main program.

In step S109, the storage battery 27 is charged and the process returns to the predetermined main program.
FIG. 7 is a diagram showing a state in which power is supplied by the system power supply 21 and the storage battery 27 is being charged.
The controller 28 supplies power to the marine power line 31 only from the system power supply 21. That is, the electric power of the system power supply 21 is converted from a high voltage to a low voltage by the transformer 36 and is supplied to the load equipment 37. The controller 28 further charges the storage battery 27 with the power from the system power supply 21. That is, the electric power of the system power supply 21 is converted from a high voltage to a low voltage by the transformer 25, and from AC to DC by the power converter 26, and the storage battery 27 is charged.

In step S110, power is supplied from both the grid power source 21 and the storage battery 27 as land power, and the process returns to the predetermined main program.
FIG. 8 is a diagram showing a state in which power is supplied from both the system power supply 21 and the storage battery 27.
Here, too, the cable 15 is connected to the connector 14, and in the ship electrical line 31, the switch 32 is closed, the switch 33 is open, and the switch 35 is closed. The controller 28 closes the switch 23 and the switch 24 when the power consumption Wc is equal to or higher than the threshold value W1, and supplies power to the marine power line 31 from both the system power supply 21 and the storage battery 27. That is, the power of the storage battery 27 is converted from direct current to alternating current by the power converter 26, and from a low voltage to a high voltage by the transformer 25, and the power is supplied to the land power line 22. In this way, the electric power obtained by adding the electric power of the storage battery 27 to the electric power of the system power supply 21 is converted from a high voltage to a low voltage by the transformer 36 and is supplied to the load equipment 37.

"motion"
Next, a series of operations of the embodiment will be described.
FIG. 9 is a time chart showing the operation of the embodiment.
Here, the power supply Ws of the system power supply 21, the power supply Wb of the storage battery 27, the total sum Wt of the power supply, and the power consumption Wc of the ship 12 are shown. The power supply Wb of the storage battery 27 has a positive value when discharging, and a negative value when storing electricity.
When the ship 12 is not berthed and is not berthed, the storage battery 27 is charged by the system power supply 21, and charging of the storage battery 27 is completed by the time the ship 12 comes to the berth. The ship 12 is self-sufficient with the power required by the load equipment 37 using the generator 34 .

When the ship 12 docks at time t1 and the cable 15 is connected to the connector 14, only the power Ws from the system power supply 21 is supplied to the ship 12 as land power.
When the power consumption Wc of the ship 12 increases and becomes equal to or higher than the threshold value W1 at time t2, the total power Wt, which is the sum of the power supply Ws from the grid power supply 21 and the power Wb from the storage battery 27, is supplied to the ship 12 as shore power. be done. Thereby, even if the power consumption Wc of the ship 12 further increases, the power supply Wb of the storage battery 27 only increases, and the power supply Ws of the system power supply 21 does not exceed the contract power Wd. While the power consumption Wc of the ship 12 is equal to or greater than the threshold value W1, the power supply Wb of the storage battery 27 increases or decreases in accordance with the increase or decrease in the power consumption Wc.

When the power consumption Wc of the ship 12 decreases and becomes less than the threshold value W1 at time t3, only the power Ws supplied by the system power supply 21 is supplied to the ship 12 again as shore power.
When the cable 15 is cut off from the connector 14 at time t4 when the ship 12 leaves the shore, the supply of shore power to the ship 12 is stopped.
When the ship 12 leaves the shore and is not berthed, the storage battery 27 is charged again by the system power supply 21 in preparation for the next berth. The ship 12 is again self-sufficient with the power required by the load equipment 37 using the generator 34 .

《Effect》
Next, the main effects of the embodiment will be explained.
The land power supply system 11 includes a storage battery 27, a land power line 22, a controller 28, and a connection connector 14. The storage battery 27 is provided on land. The land power line 22 is connected to a land system power supply 21 and a storage battery 27 . The controller 28 controls the storage battery 27 and the land power line 22. The connector 14 is provided on land and connects the cable 15 of the anchored ship 12 to connect the land power line 22 and the ship power line 31 in the ship 12. The controller 28 supplies power to the marine power line 31 from the system power supply 21 and the storage battery 27 connected to the land power line 22 when the land power line 22 and the marine power line 31 are connected. Thereby, even if power demand increases temporarily within the ship 12, it is possible to level out the power consumption Wc so that it does not exceed the contract power Wd. In other words, by using previously stored electricity when electricity demand increases, a peak shift can be realized, and it is possible to suppress payment of contract excess charges and increase in contract charges.

The controller 28 charges the storage battery 27 from the system power supply 21 before the ship 12 docks. This makes it possible to prepare for power supply after berthing.
The controller 28 sets a predetermined threshold value W1 within a range less than the contract power Wd, and supplies power to the marine power line 31 only from the system power source 21 when the power consumption Wc of the ship 12 is less than the threshold value W1. Thereby, power supply from the system power supply 21 can be given priority, and power supply from the storage battery 27 can be suppressed to a minimum. That is, by not supplying power from the storage battery 27 more than necessary, the life of the storage battery 27 can be extended.

The controller 28 supplies power to the marine power line 31 from both the system power supply 21 and the storage battery 27 when the power consumption Wc of the vessel 12 is equal to or greater than the threshold value W1. Thereby, even if power demand increases temporarily within the ship 12, it is possible to level out the power consumption Wc so that it does not exceed the contract power Wd.
The controller 28 sets a predetermined threshold value W2 in a range less than the threshold value W1, and when the ship 12 is at anchor, the controller 28 sets a predetermined threshold value W2 in a range less than the threshold value W1. The storage battery 27 is charged from the system power supply 21 within a range where the sum of the power and the power consumption Wc of the ship 12 does not exceed the threshold value W1. Thereby, it is possible to avoid a decrease in the state of charge of the storage battery 27 while the ship 12 is at anchor, and to increase the state of charge of the storage battery 27 in case the demand for electric power increases within the ship 12.

The controller 28 supplies power to the marine power line 31 only from the storage battery 27 when there is an abnormality in the system power supply 21. Thereby, it is possible to back up the system power supply 21 and improve the reliability of power supply.
The storage battery 27 is housed in the container 13. This enables intermodal transport and facilitates installation at port mooring facilities. Furthermore, not only is quality stable, but many of the processes associated with packaging are completed at the factory, which greatly reduces on-site work, shortens construction time, and suppresses increases in costs.
Controller 28 controls charging and discharging of storage battery 27 via power converter 26 . Thereby, charging and discharging of the storage battery 27 can be arbitrarily controlled, and stable power can be supplied to the load equipment 37.

In the shore power supply method, when the shore power line 22 and the ship electric line 31 are connected by connecting the cable 15 of the anchored ship 12 to the shore connection connector 14, the system power supply connected to the shore power line 22 is connected. 21 and the storage battery 27 supply power to the ship electrical line 31. Thereby, even if power demand increases temporarily within the ship 12, it is possible to level out the power consumption Wc so that it does not exceed the contract power Wd. In other words, by using previously stored electricity when electricity demand increases, a peak shift can be realized, and it is possible to suppress payment of contract excess charges and increase in contract charges.

《Comparative example》
Next, a comparative example will be explained.
FIG. 10 is a diagram showing a land power supply system 41 of a comparative example.
Here, except for omitting the switch 24, the transformer 25, the power converter 26, and the storage battery 27, the configuration is similar to that of the above-described embodiment, so a detailed explanation of the common parts will be omitted. do.
Since the land power supply system 41 does not include the storage battery 27, it has no choice but to supply power to the marine power line 31 only from the grid power supply 21.

FIG. 11 is a time chart showing the operation of the comparative example.
Here, the power supply Ws of the system power supply 21 and the power consumption Wc of the ship 12 are shown. When the ship 12 docks at time t1 and the cable 15 is connected to the connector 14, only the power Ws supplied by the system power supply 21 is supplied to the ship 12 as shore power. After that, even if the power consumption Wc of the ship 12 increases and becomes equal to or higher than the threshold value W1 at time t2, only the power Ws supplied by the grid power supply 21 is supplied to the ship 12 as shore power, so the power Ws supplied by the grid power supply 21 is exceeds the contract power Wd. In this way, if the power consumption Wc exceeds the contracted power Wd due to a temporary increase in power demand, there is a problem that a contract excess fee may be paid or the rate may increase due to a review of the contract plan. .

《Modified example》
In the above embodiment, the configuration in which the storage battery 27 is added in addition to the system power supply 21 has been described, but the present invention is not limited to this. In addition, as renewable energy, for example, power obtained from solar power generation, wind power generation, hydroelectric power generation, biomass power generation, geothermal power generation, etc. may be supplied to the ship's power line 31 or the storage battery 27 may be charged.
In the above embodiment, the high-voltage system power supply 21 with an AC voltage of more than 600V and less than 7,000V has been described, but the present invention is not limited to this. It can also be applied to low voltages below 600V AC and extra high voltages exceeding 7,000V AC. In the case of extra high voltage, extra high voltage power receiving equipment is also accommodated in the container 13.
Although the above embodiment describes a configuration in which the controller 28 is housed in the container 13, the present invention is not limited to this. That is, the controller 28 may be remotely operated from the outside via communication.

In the above embodiment, a case has been described in which the land power line 22 is not provided with a frequency converter, but the invention is not limited to this, and the land power line 22 may be provided with a frequency converter. The frequency conversion device is also called a constant voltage constant frequency device (CVCF), and includes a rectifier, a filter circuit, and an inverter circuit. By providing such a frequency conversion device, the voltage and frequency of the power supplied to the ship 12 can be kept constant, so that more stable power can be supplied.
In the above embodiment, a configuration in which the ship's electric line 31 is an AC circuit has been described, but the ship's electric line 31 may be a DC circuit. In that case, the power of the system power supply 21 may be converted from alternating current to direct current by a power converter and supplied to the marine power line 31, and the power of the storage battery 27 may be supplied to the marine power line 31 as direct current via the voltage regulator.

Although the embodiments have been described above with reference to a limited number of embodiments, the scope of rights is not limited thereto, and modifications of the embodiments based on the above disclosure will be obvious to those skilled in the art.

DESCRIPTION OF SYMBOLS 11...Land power supply system, 12...Ship, 13...Container, 14...Connector, 15...Cable, 16...Reel, 21...System power supply, 22...Land electric line, 23...Switch, 24...Switch, 25... Transformer, 26... Power converter, 27... Storage battery, 28... Controller, 31... Ship electrical line, 32... Switch, 33... Switch, 34... Generator, 35... Switch, 36... Transformer, 37... Load Equipment, 38...Controller, 41...Land power supply system

Claims (9)

A storage battery installed on land,
a land power line to which a land system power source and the storage battery are connected;
a control unit that controls the storage battery and the land power line;
A connector provided on land and connected to a cable of a berthed ship to connect the land power line and a ship power line in the ship,
The above-mentioned control unit supplies power to the marine power line from the system power supply and the storage battery connected to the shore power line when the land power line and the marine power line are connected. supply system. The land power supply system according to claim 1, wherein the control unit charges the storage battery from the system power source before the ship docks. The control unit sets a first threshold value predetermined in a range less than the contract power, and supplies power to the ship power line only from the grid power source when the power consumption of the ship is less than the first threshold value. The land power supply system according to claim 1 or 2, characterized in that: The land-based power supply system according to claim 3, wherein the control unit supplies power to the marine power line from both the grid power supply and the storage battery when the power usage of the marine vessel is equal to or greater than the first threshold value. Power supply system. The control unit sets a predetermined second threshold within a range less than the first threshold, and when the ship is at anchor, when the power consumption of the ship is less than the second threshold, The land power supply system according to claim 3 or 4, wherein the storage battery is charged from the system power supply. The land power supply system according to any one of claims 1 to 5, wherein the control unit supplies power to the marine power line only from the storage battery when there is an abnormality in the system power supply. The land power supply system according to claim 1, wherein the storage battery is housed in a container. The land power supply system according to any one of claims 1 to 7, wherein the control unit controls charging and discharging of the storage battery via a power converter. When the shore power line and the ship electric line are connected by connecting the cable of the anchored ship to a connector on land, power is supplied to the ship electric line from the grid power supply and storage battery connected to the shore electric line. A land power supply method characterized by:

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