Underwater charging system

Abstract

An underwater charging system 1A according to one embodiment includes a seabed station 4 including a storage battery 47, and a substation 3 connected to the seabed station 4 by a cable 12. The substation 3 includes a power receiving device 34 electrically connected to the storage battery 47 via the cable 12, and a buoy 37, and is maintained at a depth defined by the length of the cable 12 by buoyancy of the buoy 37. Furthermore, the underwater charging system 1A includes a remotely operated vehicle 2 that is deployed into the sea from a support vessel 61 and includes a power transmission device 22 capable of supplying power to the power receiving device 34.

Description

Underwater charging system

[0001] The present disclosure relates to an underwater charging system capable of charging a storage battery of a subsea station.

[0002] Conventionally, a subsea station including a storage battery has been known. For example, Patent Document 1 describes charging a storage battery of a subsea station by a remotely operated vehicle (ROV) when it is difficult to lay a subsea cable. In Patent Document 1, the subsea station is called an "underwater station" and the ROV is called an "underwater robot".

[0003] Japanese Patent Application Laid-Open No. 2004-166459

[0004] The ROV is dropped into the sea from a support ship. The support ship is equipped with a cable reel that winds and pays out an umbilical cable connected to the ROV. Therefore, when the installation depth of the subsea station is deep, as the length of the umbilical cable increases, the cable reel and the support ship become larger, and the operation cost increases.

[0005] Therefore, an object of the present disclosure is to provide an underwater charging system capable of charging a storage battery of a subsea station at a low operation cost.

[0006] From a first aspect, the present disclosure provides an underwater charging system including a subsea station including a storage battery, a substation connected to the subsea station by a cable, a power receiving device electrically connected to the storage battery via the cable, and a buoy, the substation being maintained at a depth defined by the length of the cable by the buoyancy of the buoy, and a remotely operated vehicle including a power transmission device capable of supplying power to the power receiving device, the remotely operated vehicle being dropped into the sea from a support ship.

[0007] This disclosure, in a second aspect, provides an underwater charging system comprising: a submarine station including a battery and a cable reel for winding and unwinding a cable; a substation connected to the submarine station by the cable, the substation including a power receiving device electrically connected to the battery via the cable, and a buoy, wherein the cable reel winds up the cable to bring the substation adjacent to the submarine station when the battery is not being charged, and unwinds the cable to raise the substation when the battery is being charged.

[0008] According to this disclosure, an underwater charging system is provided that can charge the batteries of an underwater station at a low operating cost.

[0009] This is a schematic diagram of the underwater charging system according to the first embodiment. This diagram shows the charging of the battery of the submarine station according to the first embodiment. This is a schematic diagram of the underwater charging system according to the second embodiment. This diagram shows the charging of the battery of the submarine station according to the second embodiment.

[0010] <First Embodiment> Figure 1 shows an underwater charging system 1A according to the first embodiment. The underwater charging system 1A includes a seabed station 4 installed on the seabed and a substation 3 connected to the seabed station 4 by a cable 12. The underwater charging system 1A also includes a remotely operated vehicle (ROV) 2 and an autonomous underwater vehicle (AUV) 5.

[0011] The AUV5 includes a hull 51, a battery 57 attached to the hull 51, a control device 52, a power receiving device 54, an optical communication device 55, a docking device 56, a propulsion device 58, and an acoustic communication device 59. The AUV5 also includes an inspection device equipped with a camera for inspecting underwater structures and the seabed.

[0012] The control device 52 is electrically connected to the battery 57, the power receiving device 54, the optical communication device 55, the docking device 56, the propulsion device 58, and the acoustic communication device 59. In other words, each of the power receiving device 54, the optical communication device 55, the docking device 56, the propulsion device 58, and the acoustic communication device 59 is electrically connected to the battery 57 via the control device 52 and receives power from the battery 57.

[0013] The control device 52 controls the operation of the optical communication device 55, the docking device 56, the propulsion device 58, and the acoustic communication device 59, and also includes a processing circuit 53 that controls the charging of the battery 57 from the power receiving device 54. The processing circuit 53 records the inspection data from the inspection machine.

[0014] With respect to the control device 52 and the control devices 22, 32, and 42 described later, the functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, dedicated processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuits. In this disclosure, a circuit, unit, or means is hardware that performs the enumerated functions, or hardware programmed to perform the enumerated functions. The hardware may be hardware disclosed herein, or other known hardware that is programmed or configured to perform the enumerated functions. If the hardware is a processor, which is considered a type of circuit, then the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or the processor.

[0015] The propulsion system 58 is capable of providing thrust to the hull 51 in the longitudinal, lateral, and vertical directions, as well as providing rotational force to the hull 51 in the yaw direction around the vertical axis and in the pitch direction around the left-right axis. For example, the propulsion system 58 may include a plurality of thrusters facing different directions, a rudder for changing course, or a single swivel thruster.

[0016] The processing circuit 53 is pre-programmed with work commands for inspecting the underwater structures and seabed described above, and the processing circuit 53 controls the propulsion device 58 according to these work commands. The work commands provided to the processing circuit 53 may be updated by optical communication between the optical communication device 55 and the optical communication device 45 of the seabed station 4, which will be described later.

[0017] The acoustic communication device 59 communicates acoustically with the acoustic communication device 48 of the submarine station 4, which will be described later. As a result, the processing circuit 53 determines the relative position of the AUV 5 with respect to the submarine station 4, and controls the propulsion system 58 based on the relative position when the AUV 5 reaches the submarine station 4.

[0018] The docking device 56 includes an electric actuator that switches between engagement and disengagement with the docking device 46 of the submarine station 4, which will be described later. As shown in Figure 2, the AUV 5 is connected to the submarine station 4 when the docking device 56 of the AUV 5 engages with the docking device 46 of the submarine station 4. However, one of the docking devices 56 or 46 may be a fixed structure.

[0019] When the AUV 5 is connected to the submarine station 4, the optical communication device 55 transmits the inspection data recorded in the processing circuit 53 as an optical signal.

[0020] The submarine station 4 includes a cradle 41, a battery 47, a control device 42, a power transmission device 44, an optical communication device 45, a docking device 46, and an acoustic communication device 48, all of which are attached to the cradle 41.

[0021] A cable 12 is connected to the control device 42, and the control device 42 is electrically connected to the battery 47, the power transmission device 44, the optical communication device 45, the docking device 46, and the acoustic communication device 48. In other words, each of the power transmission device 44, the optical communication device 45, the docking device 46, and the acoustic communication device 48 is electrically connected to the battery 47 via the control device 42 and receives power from the battery 47.

[0022] The control device 42 controls the operation of the optical communication device 45, the docking device 46, and the acoustic communication device 48, and also includes a processing circuit 43 that controls the charging of the battery 47 from the cable 12.

[0023] The acoustic communication device 48 communicates acoustically with the acoustic communication device 59 of the AUV 5. The docking device 46 includes an electric actuator that switches between engagement and disengagement with the docking device 56 of the AUV 5.

[0024] The power transmission device 44 is capable of supplying power to the AUV 5's power receiving device 54 when the AUV 5 is connected to the submarine station 4. Power supply may be via contact or contactless power. At this time, the voltage and current between the battery 47 and the power transmission device 44 are controlled by the processing circuit 43.

[0025] The optical communication device 45 is capable of receiving inspection data transmitted from the optical communication device 55 of the AUV 5 when the AUV 5 is connected to the submarine station 4. The processing circuit 43 records the inspection data received by the optical communication device 45.

[0026] Substation 3 includes a frame 31, a buoy 37 attached to the frame 31, a control device 32, a power receiving device 34, an optical communication device 35, a docking device 36, and an acoustic communication device 38.

[0027] A cable 12 is connected to the control device 32, and the control device 32 is electrically connected to the power receiving device 34, the optical communication device 35, the docking device 36, and the acoustic communication device 38. In other words, each of the power receiving device 34, the optical communication device 35, the docking device 36, and the acoustic communication device 38 is electrically connected to the battery 47 via the control device 32, the cable 12, and the control device 42 of the submarine station 4, and receives power from the battery 47.

[0028] The control device 32 controls the operation of the optical communication device 35, the docking device 36, and the acoustic communication device 38, and also includes a processing circuit 43 that controls the voltage and current between the power receiving device 34 and the cable 12.

[0029] Buoy 37 provides substation 3 with a buoyancy greater than the gravitational force acting on it. In other words, substation 3 is maintained at a depth defined by the length of cable 12 by the buoyancy provided by buoy 37.

[0030] The power receiving device 34 is electrically connected to the battery 47 of the submarine station 4 via the control device 32, the cable 12, and the control device 42 of the submarine station 4. The optical communication device 35 is also electrically connected to the control device 42 of the submarine station 4 via the control device 32 and the cable 12. In other words, the cable 12 includes not only power lines but also communication lines.

[0031] The acoustic communication device 38 communicates acoustically with the acoustic communication device 28 of the ROV2, which will be described later. This allows the operator controlling the ROV2 from the support ship 61 to reach the substation 3 while knowing the relative position of the ROV2 with respect to the substation 3.

[0032] The docking device 36 includes an electric actuator that switches between engagement and disengagement of the ROV 2 with the docking device 26, which will be described later. As shown in Figure 2, the ROV 2 is connected to the substation 3 when the docking device 26 of the ROV 2 engages with the docking device 36 of the substation 3. However, one of the docking devices 26 or 36 may be a fixed structure.

[0033] When the ROV2 is connected to the substation 3, the optical communication device 35 transmits the inspection data recorded in the processing circuit 43 of the submarine station 4 as an optical signal.

[0034] The ROV2 is lowered into the sea from the support vessel 61 by a crane 62. The support vessel 61 is equipped with a cable reel 63 for winding and unwinding the umbilical cable 11 connected to the ROV2, and control devices for the operator to control the ROV2.

[0035] ROV2 includes a hull 21 and a control device 22, a power transmission device 24, an optical communication device 25, a docking device 26, a propulsion device 27, and an acoustic communication device 28 attached to the hull 21. ROV2 also includes a camera for taking underwater photographs. The operator of ROV2 controls the ROV2 while viewing the images captured by the camera.

[0036] The control device 22 is connected to an umbilical cable 11, and the control device 22 is electrically connected to the power transmission device 24, the optical communication device 25, the docking device 26, the propulsion device 27, and the acoustic communication device 28. In other words, each of the power transmission device 24, the optical communication device 25, the docking device 26, the propulsion device 27, and the acoustic communication device 28 is electrically connected to the umbilical cable 11 via the control device 22 and receives power from the umbilical cable 11.

[0037] The control device 22 controls the operation of the optical communication device 25, the docking device 26, the propulsion device 27, and the acoustic communication device 28, and also includes a processing circuit 23 that controls the voltage and current between the umbilical cable 11 and the power transmission device 24.

[0038] The propulsion system 27 is capable of providing thrust to the hull 21 in the longitudinal, lateral, and vertical directions, as well as providing turning force to the hull 21 in the yaw direction around the vertical axis and in the pitch direction around the lateral axis. For example, the propulsion system 27 may include a plurality of thrusters facing different directions, a rudder for changing course, or a single swivel thruster.

[0039] The processing circuit 23 is given an operation command from the above-described operation device via the umbilical cable 11, and the processing circuit 23 controls the propulsion device 27 according to the operation command.

[0040] The acoustic communication device 28 performs acoustic communication with the acoustic communication device 38 of the substation 3. The docking device 26 includes an electric actuator that switches between engagement and disengagement with the docking device 36 of the substation 3.

[0041] The power transmission device 24 is capable of power supply to the power reception device 34 of the substation 3 when the ROV 2 is connected to the substation 3. The power supply may be contact power supply or non-contact power supply. The voltage and current between the umbilical cable 11 and the power transmission device 24 at this time are controlled by the processing circuit 23 as described above.

[0042] The optical communication device 25 is capable of receiving inspection data transmitted from the optical communication device 35 of the substation 3 when the ROV 2 is connected to the substation 3. The processing circuit 23 records the inspection data received by the optical communication device 25.

[0043] As described above, in the underwater charging system 1A of the present embodiment, when charging the storage battery 47 of the subsea station 4, it is only necessary to bring the ROV 2 to the substation 3. Therefore, the length of the umbilical cable 11 connected to the ROV 2 may be shorter than when the ROV 2 reaches the subsea station 4, and it is not necessary to increase the size of the cable reel 63 for the umbilical cable 11 and the support ship 61. Therefore, the storage battery 47 of the subsea station 4 can be charged at a low operation cost.

[0044] Moreover, since the subsea station 4 includes a power transmission device 44 that can supply power to the power reception device 54 of the AUV 5, it is possible to charge the AUV 5 from the subsea station 4.

[0045] Furthermore, in the present embodiment, since the AUV 5, the undersea station 4, the sub-station 3, and the ROV 2 each include an optical communication device 55, 45, 35, 25, data can be transferred from the AUV 5 to the undersea station 4, and the transferred data can be recovered from the undersea station 4 using the ROV 2. Note that FIG. 2 shows a state where the AUV 5 is connected to the undersea station 4 and the ROV 2 is connected to the sub-station 3, but it is needless to say that these connections do not have to be made simultaneously.

[0046] <Second Embodiment> FIG. 3 shows an underwater charging system 1B according to the second embodiment. In the present embodiment, the undersea station 4 includes a cable reel 49 that winds and pays out the cable 12. The cable reel 49 is electrically connected to the control device 42 and is controlled by a processing circuit 43 of the control device 42.

[0047] When the storage battery 47 of the undersea station 4 is not being charged, as shown in FIG. 3, the processing circuit 43 controls the cable reel 49 so that the cable reel 49 winds up the cable 12 to bring the sub-station 3 adjacent to the undersea station 4. Here, "the sub-station 3 is adjacent to the undersea station 4" means that the sub-station 3 is located within 10 m from the undersea station 4.

[0048] On the other hand, when the storage battery 47 of the undersea station 4 is being charged, the processing circuit 43 controls the cable reel 49 so that the cable reel 49 pays out the cable 12 to lift the sub-station 3, as shown in FIG. 4.

[0049] In the present embodiment, the cable reel 49 lifts the sub-station 3 to the sea surface. For this reason, the underwater charging system 1B does not include the ROV 2, and the power receiving device 34 is merely a connector. Further, the sub-station 3 includes a connector 39 for data transfer instead of the optical communication device 35.

[0050] In this embodiment, when charging the battery 47 of the subsea station 4, charging can be performed via the substation 3 by lifting the substation 3 onto the support vessel 61 using the crane 62. Therefore, the battery 47 of the subsea station 4 can be charged at a low operating cost.

[0051] Furthermore, since the submarine station 4 includes a power transmission device 44 that can supply power to and from the AUV 5's power receiving device 54, it is possible to charge the AUV 5 from the submarine station 4.

[0052] Furthermore, in this embodiment, as in the first embodiment, the AUV 5 and the submarine station 4 each include optical communication devices 55 and 45, so that data can be transferred from the AUV 5 to the submarine station 4. The transferred data can be recovered through the connector 39 when the substation 3 is brought aboard the support vessel 61.

[0053] <Modification> When charging the battery 47 of the submarine station 4, the cable reel 49 raises the substation 3 to a depth lower than the sea surface, and the underwater charging system 1B may include the ROV 2. In this case, similar to the first embodiment, the substation 3 includes an optical communication device 35 instead of a connector 39, and the power receiving device 34 is configured to be able to receive power from the power transmitting device 24 of the ROV 2.

[0054] If the underwater charging system 1B includes an ROV 2, the ROV 2 only needs to reach the substation 3 when charging the battery 47 of the submarine station 4. Therefore, the length of the umbilical cable 11 connected to the ROV 2 can be shorter than when the ROV 2 is brought to the submarine station 4, and there is no need to enlarge the cable reel 63 for the umbilical cable 11 and the support vessel 61. Consequently, the battery 47 of the submarine station 4 can be charged at a low operating cost.

[0055] <Other Embodiments> This disclosure is not limited to the embodiments described above, and various modifications are possible without departing from the gist of this disclosure.

[0056] For example, in either the first or second embodiment, the AUV 5 may not be used, and the submarine station 4 may include observation instruments such as a seismometer, thermometer, densitometer, sonar, and camera, and the observation data from the observation instruments may be recorded in the processing circuit 43. In this case, the power transmission device 44 and optical communication device 45 of the submarine station 4 are unnecessary.

[0057] <Summary> In a first aspect, the present disclosure provides an underwater charging system comprising: a subsea station including a battery; a substation connected to the subsea station by a cable, the substation including a power receiving device electrically connected to the battery via the cable, and a buoy, the substation being maintained at a depth defined by the length of the cable by the buoyancy of the buoy; and a remotely operated vessel, which is dropped into the sea from a support vessel and includes a power transmitting device capable of supplying power to and from the power receiving device.

[0058] With the above configuration, when charging the battery, it is sufficient to have the remotely operated vehicle (ROV) reach the substation. Therefore, the length of the umbilical cable connected to the ROV can be shorter than when the ROV is brought to the subsea station, and there is no need to enlarge the cable reel and support vessel for the umbilical cable. Consequently, the battery of the subsea station can be charged at a low operating cost.

[0059] In a second embodiment, in the first embodiment, the storage battery is a first storage battery, the power receiving device is a first power receiving device, and the underwater charging system further comprises an autonomous underwater vehicle including a second storage battery and a second power receiving device electrically connected to the second storage battery, and the seabed station may include a power transmission device that is electrically connected to the first storage battery and capable of supplying power to and from the second power receiving device. With this configuration, charging of the autonomous underwater vehicle (AUV) from the seabed station is possible.

[0060] In a third embodiment, in the first embodiment, the subsea station may include a processing circuit for recording data, the substation may include a first optical communication device for transmitting the data recorded in the processing circuit as an optical signal, and the remotely operated vehicle may include a second optical communication device capable of receiving data transmitted from the first optical communication device. With this configuration, data can be retrieved from the subsea station using an ROV.

[0061] In a fourth embodiment, in the second embodiment, the autonomous underwater vehicle includes a first processing circuit for recording data and a lower first optical communication device for transmitting the data recorded in the first processing circuit as an optical signal; the seabed station includes a lower second optical communication device capable of receiving data transmitted from the lower first optical communication device and a second processing circuit for recording the data received by the lower second optical communication device; the substation includes an upper first optical communication device for transmitting the data recorded in the second processing circuit as an optical signal; and the remotely operated vehicle may include an upper second optical communication device capable of receiving data transmitted from the upper first optical communication device. With this configuration, data can be transferred from the AUV to the seabed station, and the transferred data can be retrieved from the seabed station using an ROV.

[0062] In a fifth aspect, and in a second aspect, the present disclosure provides an underwater charging system comprising: a submarine station including a battery and a cable reel for winding and unwinding a cable; a substation connected to the submarine station by the cable, the substation including a power receiving device electrically connected to the battery via the cable, and a buoy, wherein the cable reel winds up the cable to bring the substation adjacent to the submarine station when the battery is not being charged, and unwinds the cable to raise the substation when the battery is being charged.

[0063] With the above configuration, when the substation is raised to the sea surface for battery charging, charging can be performed via the substation by pulling it onto a support vessel. On the other hand, when the substation is raised to a depth lower than the sea surface for battery charging, a remotely operated vehicle (ROV) can be brought to the substation. For this reason, the length of the umbilical cable connected to the ROV can be shorter than when the ROV is brought to the subsea station, and there is no need to enlarge the cable reel for the umbilical cable or the support vessel. Consequently, in either case, the batteries of the subsea station can be charged at a low operating cost.

[0064] In a sixth embodiment, in the fifth embodiment, the storage battery is a first storage battery, the power receiving device is a first power receiving device, and the underwater charging system further comprises an autonomous underwater vehicle including a second storage battery and a second power receiving device electrically connected to the second storage battery, and the seabed station may include a power transmission device that is electrically connected to the first storage battery and capable of supplying power to and from the second power receiving device. With this configuration, charging of the autonomous underwater vehicle (AUV) from the seabed station is possible.

[0065] In a seventh aspect, in the sixth aspect, the autonomous underwater vehicle includes a first processing circuit for recording data and a first optical communication device for transmitting the data recorded in the first processing circuit as an optical signal, and the submarine station may include a second optical communication device capable of receiving data transmitted from the first optical communication device and a second processing circuit for recording the data received by the second optical communication device. With this configuration, data can be transferred from the AUV to the submarine station.

[0066] 1A, 1B Underwater charging system 11 Umbilical cable 12 Cable 2 Remotely operated vehicle (ROV) 22 Control device 23 Processing circuit 24 Power transmission device 25 Optical communication device 3 Substation 32 Control device 33 Processing circuit 34 First power receiving device 35 First optical communication device 37 Buoy 4 Subsea station 42 Control device 43 Processing circuit 44 Power transmission device 45 Optical communication device 47 Battery 49 Cable reel 5 Autonomous underwater vehicle (AUV) 52 Control device 53 Processing circuit 54 Power receiving device 55 Optical communication device 57 Battery 61 Support vessel 63 Cable reel

Claims

1. An underwater charging system comprising: a subsea station including a battery; a substation connected to the subsea station by a cable, the substation including a power receiving device electrically connected to the battery via the cable, and a buoy, the substation being maintained at a depth defined by the length of the cable by the buoyancy of the buoy; and a remotely operated vehicle, which is dropped into the sea from a support vessel and includes a power transmission device capable of supplying power to and from the power receiving device.

2. The underwater charging system according to claim 1, wherein the storage battery is a first storage battery, the power receiving device is a first power receiving device, and the system further comprises an autonomous underwater vehicle including a second storage battery and a second power receiving device electrically connected to the second storage battery, and the underwater station includes a power transmission device that is electrically connected to the first storage battery and capable of supplying power to and from the second power receiving device.

3. The underwater charging system according to claim 1, wherein the subsea station includes a processing circuit for recording data, the substation includes a first optical communication device for transmitting the data recorded in the processing circuit as an optical signal, and the remotely operated vehicle includes a second optical communication device capable of receiving data transmitted from the first optical communication device.

4. The underwater charging system according to claim 2, wherein the autonomous underwater vehicle includes a first processing circuit for recording data and a lower first optical communication device for transmitting the data recorded in the first processing circuit as an optical signal; the seabed station includes a lower second optical communication device capable of receiving data transmitted from the lower first optical communication device and a second processing circuit for recording the data received by the lower second optical communication device; the substation includes an upper first optical communication device for transmitting the data recorded in the second processing circuit as an optical signal; and the remotely operated vehicle includes an upper second optical communication device capable of receiving data transmitted from the upper first optical communication device.

5. An underwater charging system comprising: a submarine station including a battery and a cable reel for winding and unwinding a cable; a substation connected to the submarine station by the cable, the substation including a power receiving device electrically connected to the battery via the cable, and a buoy, wherein the cable reel winds up the cable to bring the substation adjacent to the submarine station when the battery is not being charged, and unwinds the cable to raise the substation when the battery is being charged.

6. The underwater charging system according to claim 5, wherein the storage battery is a first storage battery, the power receiving device is a first power receiving device, and the system further comprises an autonomous underwater vehicle including a second storage battery and a second power receiving device electrically connected to the second storage battery, and the underwater station includes a power transmission device that is electrically connected to the first storage battery and capable of supplying power to and from the second power receiving device.

7. The underwater charging system according to claim 6, wherein the autonomous underwater vehicle includes a first processing circuit for recording data and a first optical communication device for transmitting the data recorded in the first processing circuit as an optical signal, and the underwater station includes a second optical communication device capable of receiving data transmitted from the first optical communication device and a second processing circuit for recording the data received by the second optical communication device.

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