Electrical system for an unmanned underwater vehicle

Abstract

The present invention relates to an unmanned underwater vehicle (10) having an on-board electrical system (40) and a shore connection (20), wherein the on-board electrical system (40) can be electrically connected to the shore connection (20) via a first switching device (31), characterized in that the shore connection (20) has a first connection group (21) and a second connection group (22), wherein the first connection group (21) is designed for connection to the on-board electrical system (40), wherein the second connection group (22) is connected to the first switching device (31) in order to actuate the first switching device (31), wherein, in the non-actuated state, the first switching device (31) disconnects the connection between the on-board electrical system (40) of the first connection group (21).

Description

[0001] Electrical network for an unmanned underwater vehicle

[0002] The invention relates to an electrical network for an unmanned underwater vehicle.

[0003] Electrical networks are familiar for submarines. Here, safety functions are also performed by the crew, for example, manually disconnecting connections after manually checking the safety of the disconnection. However, in an unmanned underwater vehicle, humans are no longer required as a control authority, so the systems must be intrinsically safe and functional.

[0004] Underwater vehicles have what is known as a shore connection, which supplies the underwater vehicle with electrical energy and can be used to charge energy storage devices. This makes it possible to charge the underwater vehicle via the shore connection from an external system, such as a power grid. This is necessary when starting up for the first time, and is also used in port to charge batteries. For this purpose, the shore connection must be connectable to the on-board power supply. However, if there is no connection between the shore connection and the on-board power supply, voltage will be present at the contacts of the shore connection, which in turn poses a risk to a person who wants to connect a charging connection to the shore connection and who therefore does not yet have a plug in the shore connection to protect the contacts from accidental contact.Secondly, water can also cause a short circuit if there is no plug in the shore power connector, but the shore power connector is connected to the onboard electrical system. In a manned submarine, the crew can check this and thus ensure safety.

[0005] From DE 10 2011 107 824 A1 a device and a method for operating an unmanned underwater vehicle as well as an underwater vehicle with such a device are known.

[0006] DE 10 2018 215 579 A1 discloses a charging device for an electrically powered vehicle, an on-board power supply, and such a vehicle. CN 1 03 885 391 A discloses a small autonomous underwater robot energy supply management system.

[0007] From DE 10 2022 205 773 A1 a submarine with two different battery systems and a method for operating them is known.

[0008] From CN 1 08 045 530 A an underwater robot for detecting underwater cables and an operating method for this purpose are known.

[0009] A submarine with two converters on the traction motor is known from DE 10 2022 204 905 B3.

[0010] WO 02 / 015 361 A1 discloses a device for immediate shutdown in the event of short circuits in electronic direct current and alternating current networks of surface and underwater vessels, in particular combat ships, and offshore installations.

[0011] The object of the invention is to create a safe electrical system for an unmanned underwater vehicle.

[0012] This object is achieved by the unmanned underwater vehicle having the features specified in claim 1. Advantageous further developments emerge from the subclaims, the following description, and the drawings.

[0013] The unmanned underwater vehicle according to the invention has an on-board electrical system. The on-board electrical system serves to distribute the electrical energy on board the unmanned underwater vehicle. The unmanned underwater vehicle also has a shore connection. Electrical energy can be supplied externally via the shore connection in order to charge the unmanned underwater vehicle from the outside. Energy can also be withdrawn via the shore connection if necessary, for example to deliberately discharge a battery during a maintenance cycle. The shore connection thus represents the interface of the on-board electrical system to the outside world. The on-board electrical system can be electrically connected to the shore connection via a first switching device. Since the shore connection thus provides a contact option to the on-board electrical system, the electrical contact is normally broken via the first switching device, so that no voltage is applied to the shore connection in the normal state.This is also usually the case in a normal submarine. In a submarine, the first switching device can be operated by the crew from inside. However, with an unmanned underwater vehicle, this option is not available, or rather, it would be highly impractical if a person had to first enter the interior of the unmanned underwater vehicle, which is not usually designed for this, as the space would normally be wasted and would generate considerable buoyancy.

[0014] According to the invention, the shore power connection has a first connection group and a second connection group. A connection group is understood to be a group of electrical contacts. In the simplest case, a connection group can therefore consist of a positive pole and a negative pole, i.e. of two contacts. With three-phase current, a connection group usually has three contacts. A connection group therefore represents a unit, with all contacts of a connection group being required to establish the electrical contact. The first connection group is designed for the connection to the on-board electrical system. The first connection group therefore has the necessary contacts for establishing an electrical connection with the on-board electrical system. The first connection group therefore usually has two contacts (plus and minus). The second connection group is connected to the first switching device to control the first switching device.For example, it is the voltage supply for a motor or a switching element in order to specifically establish the electrical connection between the on-board electrical system and the shore connection from the outside and only when a connection to the shore contact exists. The first switching device breaks the connection between the on-board electrical system and the first connection group when not activated. This means that the electrical connection between the on-board electrical system and the shore connection, specifically between the on-board electrical system and the first connection group of the shore connection, can only exist if a plug connection is inserted in the shore connection, and in this way an active connection to the first switching device can be established via the second connection group. This ensures reliable contact with the shore connection, so that exposed contacts of the shore connection can never have any voltage applied from the on-board electrical system.This second connection group thus prevents a person from accessing the interior to establish or disconnect the connection between the first connection group and the on-board power supply. This allows for safe and simple securing and activation of the first connection group via the second connection group without a person being inside the unmanned underwater vehicle. The invention therefore replaces an internally arranged switching device with the second connection group, allowing for easy access and eliminating the need for access to the interior.

[0015] Combining the two connection groups in a single shore power connection ensures safety, as both connection groups are connected simultaneously by inserting a plug connection, thus protecting them from external contact. This means that the first connection group can only be live if it is appropriately de-energized via the second connection group. This, in turn, means that the shore power plug is plugged into the first connection group, thus protecting it from access and thus from accidental electric shock.

[0016] The first switching device therefore has no electrical connection to the on-board power supply to switch the first switching device itself. This means that the first switching device cannot be closed from within, i.e., from the unmanned underwater vehicle, thus preventing unwanted voltage from being applied to the shore connection.

[0017] The shore connection is preferably a single connection, i.e. a connection into which a plug is inserted, which, on the one hand, connects all connections of all connection groups simultaneously when plugged in, but on the other hand, also mechanically protects them from the outside. While it would also be possible, in particular, to first establish the connection to the first connection group and then to the second connection group in two separate plug-in processes, this carries the risk that only the second connection group is connected, leaving the contacts of the first connection group unprotected and connected to the on-board electrical system. Therefore, the first connection group and the second connection group can preferably only be contacted from the outside via a common plug.

[0018] This makes it easy to avoid human inspection or intervention, while still ensuring that no dangerous voltage can be present at the open contacts of the shore connection. It also eliminates the need to check the switching status of the first switching device, assuming this were even possible.

[0019] In a further embodiment of the invention, the on-board electrical system has at least a first sub-network and a second sub-network. The design with at least two sub-networks is common for submarines, as this allows redundancy to be created. The systems are usually designed so that even if one sub-network fails, all essential systems are still available, at least to a limited extent, so that, for example, at least surfacing is still possible. This can be achieved, for example, by connecting an energy source such as a battery and part of the propulsion motor to each electrical sub-network. The first sub-network and the second sub-network are electrically connectable via a second switching device. As a rule, it would be preferable to keep the first sub-network and the second sub-network electrically separate. The shore connection can only be connected to the first sub-network.This makes it possible, for example, to initially supply only the first sub-network with electrical energy when the unmanned underwater vehicle is switched on for the first time. Then, during boot-up, to also switch the second switching device connecting the first sub-network and the second sub-network, thus enabling all functions on the second sub-network to be started up. Likewise, during normal operation, batteries connected to the first sub-network and batteries connected to the second sub-network can be charged in this way, for example. Since both processes, the initial boot-up and charging in port, do not occur in critical situations, redundancy is not relevant at this time, and connecting the two sub-networks to a single on-board network does not pose a safety disadvantage. In a further embodiment of the invention, the shore connection is arranged so that it is accessible from the outside.This means that the shore connection is not located inside the underwater vehicle, especially not inside a pressure hull, for example, but is accessible from the surface. However, for flow reasons, the shore connection can be located behind a cover for normal operation. In particular, the cover can be designed to be watertight so that no water gets into the contacts and corrodes them during diving. The cover is then of course also accessible from the outside, so that the shore connection also remains accessible from the outside. The advantage is that no person has to enter the unmanned underwater vehicle to make the connection. At the same time, however, this also presents the challenge that the shore connection must not be live unless it is connected to a corresponding connection, which secures the contacts again.Since the shore connection has the first connection group and the second connection group, the second connection group is also easily accessible from the outside.

[0020] In a further embodiment of the invention, the unmanned underwater vehicle is a modular underwater vehicle. Modular systems can be easily and efficiently adapted to different operational tasks by selecting and combining modules for the underwater vehicle's task from a group of different modules. For example, the range can be increased by adding additional tank or battery modules, and adaptation to the task can be achieved by selecting a task-specific payload module. The modules can have the same external dimensions, although larger modules, for example twice the length, can be used instead of two smaller modules. The connections for the on-board power supply are preferably located at the same point on the module, as are attachment points for the mechanical connection. Standardization ensures unlimited interchangeability.However, this does not have to be the case for all modules. The underwater vehicle's modules also all have the same input voltage. Modules that do not require an electrical network can simply pass the on-board network through. The on-board network is routed serially through the modules. This eliminates the need for a rigid core structure, which in turn allows for more flexible adjustment of the number of modules used. The on-board network is preferably designed as a closed ring. This has the advantage that even if one module fails, all other modules remain connected to the on-board network.

[0021] In a further embodiment of the invention, at least one module has a module electrical system. The module electrical system can be electrically connected to the vehicle electrical system via a third switching device. The advantage of this embodiment is that the vehicle electrical system continues to function through this module, even if the module electrical system experiences a fault, such as a short circuit. In this case, the module fails because the module electrical system is disconnected from the vehicle electrical system by the third switching device, but the transmission of the vehicle electrical system through the module remains unaffected.

[0022] In a further embodiment of the invention, at least one module has at least one fourth switching device. The fourth switching device is arranged at the point where the vehicle electrical system enters the module. Due to the preferred ring-shaped design of the vehicle electrical system, the module therefore preferably has a first fourth switching device and a second fourth switching device, each at both points at which the vehicle electrical system is connected to the module. This allows the module as a whole to be completely electrically disconnected from the vehicle electrical system, thereby also severing the vehicle electrical system at that point, which is why a ring-shaped design of the vehicle electrical system is advantageous because the failure of one module does not affect the others.

[0023] In a further embodiment of the invention, the unmanned underwater vehicle has at least one first drive device. The first drive device is connected to the on-board electrical system via a first converter. Preferably, the first converter is a direct current / alternating current converter. More preferably, the unmanned underwater vehicle has at least one second drive device. The second drive device is connected to the on-board electrical system via a second converter. This creates redundancy. If the on-board electrical system has a first sub-network and a second sub-network, the first drive device is preferably connected to the first sub-network and the second drive device is preferably connected to the second sub-network.

[0024] In a further embodiment of the invention, the first converter is designed to detect a short circuit in the power supply unit arranged downstream of the converter by detecting when the required current flow is not achieved. Since the first converter can only conduct a limited current, in the event of a short circuit this can lead to, for example, a fuse not being able to blow. Therefore, the control of the first converter is preferably designed such that it detects that the requested current (in the event of a short circuit this would approach infinity) cannot be provided. In order to reliably identify a short circuit, a period of time can be defined, for example 1 s, during which this current cannot be provided. This means that extremely short requirements are not critical.The time window is nevertheless chosen so short that the short-circuit current does not cause critical overheating, thus preventing a fire safely and reliably. An optional second first converter would preferably be analog.

[0025] In a further embodiment of the invention, the unmanned underwater vehicle has at least one first rudder. The first rudder is connected to the on-board power supply via a first second converter. Preferably, the first second converter is a DC-DC converter. More preferably, the unmanned underwater vehicle has at least one second rudder. The second rudder is connected to the on-board power supply via a second second converter. This creates redundancy. If the on-board power supply has a first sub-network and a second sub-network, the first rudder is preferably connected to the first sub-network and the second rudder is preferably connected to the second sub-network.

[0026] In a further embodiment of the invention, the first second converter is designed to detect a short circuit in the power supply unit arranged downstream of the converter by detecting when the required current flow is not achieved. Since the first second converter can only conduct a limited current, in the event of a short circuit this can lead to, for example, a fuse not being able to blow. Therefore, the control of the first second converter is preferably designed such that it detects that the requested current (in the event of a short circuit this would approach infinity) cannot be provided. In order to reliably identify a short circuit, a period of time can be defined, for example 1 s, during which this current cannot be provided. This means that extremely short requirements are not critical.The time window is nevertheless chosen so short that the short-circuit current does not cause critical overheating, thus preventing a fire safely and reliably. An optional second converter would preferably be analog.

[0027] In a further embodiment of the invention, the unmanned underwater vehicle has at least one first energy storage device. In particular, the first energy storage device can have a plurality of accumulators connected both in parallel (to increase the current) and in series (to increase the voltage). The first energy storage device is connected to the on-board electrical system via a first third converter. Galvanic isolation between the first energy storage device and the on-board electrical system is possible via the first third converter, preferably a DC-DC converter. In addition, an on-board electrical system voltage can be selected independently of the charge state of the first energy storage device. The unmanned underwater vehicle can further have a second energy storage device. In particular, the second energy storage device can have a plurality of accumulators connected both in parallel (to increase the current) and in series (to increase the voltage).The second energy storage device is connected to the vehicle electrical system via a second or third converter. If the vehicle electrical system has a first sub-network and a second sub-network, the first energy storage device is preferably connected to the first sub-network, and the second energy storage device is preferably connected to the second sub-network.

[0028] In a further embodiment of the invention, the unmanned underwater vehicle has at least a first fuel cell device. Fuel cell devices have proven to be a particularly suitable energy source independent of ambient air and can be operated, for example, with hydrogen and oxygen. To maintain weight neutrality, the reaction water produced is preferably stored on board the unmanned underwater vehicle. The first fuel cell device is connected to the on-board electrical system via a fourth converter. The fourth converter is preferably a direct current-to-direct current converter. This enables the feeding of electrical energy from an energy storage device and a fuel cell device into the on-board electrical system, independent of power and landing state.

[0029] In a further embodiment of the invention, the first switching device is connected to the second switching device via a connection control device. This makes it possible to establish a targeted connection between the shore connection and the respective sub-grids from the outside. The electrical connection must then be designed accordingly to enable this. For example, a connection can already be established between the first sub-grid and the second sub-grid in order to connect both sub-grids to the shore connection and supply them with energy simultaneously. Preferably, however, it can be provided that the first switching device interacts with the second switching device in such a way that one sub-grid is connected to the shore connection and charged first, and then the second sub-grid. The sub-grids are then separated from one another. If, in this case, a fault occurs in one of the sub-grids, the other sub-grid is not affected.In particular, the second connection group can then additionally comprise connection elements for a data line with which the connection control device can be controlled to switch the second switching device in order to connect all sub-networks simultaneously or individual sub-networks one after the other to the land connection.

[0030] In a further embodiment of the invention, the first switching device is connected to a central control device. The central control device can be connected, for example, to current and / or voltage sensors, test contacts on the modules, temperature sensors, battery management systems, and the like. The central control device enables monitoring of the on-board electrical system and at least some essential components connected to the on-board electrical system. In this way, a controlled energy supply to the unmanned underwater vehicle can be achieved and the charging process can be monitored. The central control device can also be connected to the first switching device and disconnect the connection if malfunctions or errors are detected via the sensors.In a further embodiment of the invention, the shore connection has a third connection group, wherein the third connection group has a connecting element for a data line. The third connection group is connected, for example, to a central control device. This allows the boat's status to be monitored externally, thus ensuring an optimized power supply via the first connection group. For example, the supplied electrical energy can be optimally adapted to the charge level and the current demand of the most important consumers.

[0031] In a further embodiment of the invention, the first switching device is a converter, in particular a DC-DC converter. This allows for voltage adjustment between the external voltage and the voltage applied to the vehicle's electrical system. This allows for optimal adjustment, for example, and in particular, of charging currents. At the same time, this allows for easier adaptation to different ports, for example, in countries with a typical 220 V or 110 V mains voltage.

[0032] In a further embodiment of the invention, the first switching device is designed such that it opens when no voltage is applied to the first connection group. This can be achieved, in particular, with semiconductor switching elements. In a further embodiment of the invention, the first switching device is designed such that the same voltage is applied to the first connection group and the second connection group onshore. This simplifies onshore expansion.

[0033] In a further embodiment of the invention, the shore connection can be sealed in a water- and pressure-tight manner. This makes it easy to prevent corrosion on the electrical contact surfaces during submersible operations. The unmanned underwater vehicle according to the invention is explained in more detail below using exemplary embodiments illustrated in the drawings.

[0034] Fig. 1 first example

[0035] Fig. 2 second example

[0036] The illustrations are purely schematic and not to scale, and serve only to illustrate the invention. For simplicity, identical parts are designated by identical reference numerals.

[0037] Fig. 1 shows a first example of an unmanned underwater vehicle 10. The on-board electrical system 40, consisting of the first sub-network 41 and the second sub-network 42, of the unmanned underwater vehicle 10 has a first sub-network 41 and a second sub-network 42. A first drive device 51 is connected to the first sub-network 41 via a first converter 61, and a first energy storage device 71 is connected via a first converter 81. A second drive device 52 is connected to the second sub-network 42 via a first converter 62, and a second energy storage device 72 is connected via a second converter 82. The first drive device 51 and the second drive device 52 can also be a common drive device with electrically separate components. In addition, the unmanned underwater vehicle 10 has a first fuel cell device 90, which is connected to a hydrogen tank 92 and an oxygen tank 93.The electrical energy generated in the first fuel cell device 90 can be fed into either the first sub-network 41 or the second sub-network 42 via a first fourth converter 91. The first sub-network 41 and the second sub-network 42 can be electrically connected to one another via a second switching device 32, but are generally electrically separated.

[0038] The unmanned underwater vehicle 10 has a shore connection 20. The shore connection 20 has a first connection group 21 and a second connection group 22. For example, the first connection group 21 has two contacts, one for the positive pole and one for the negative pole. Electrical energy can be introduced into the on-board electrical system 40, more precisely into the first sub-network 41, via the first connection group. Contact between the first connection group 21 of the shore connection 20 and the first sub-network 41 of the on-board electrical system 40 can be achieved by closing the first switching device 31. To switch the first switching device 31, the shore connection has a second connection group 22. This has the contacts necessary for switching the first switching device 31.Thus, an electrical connection between the first subnetwork 41 of the on-board network 40 and the first connection group 21 of the shore connection 20 can only exist if a corresponding plug is inserted into the shore connection 20, thereby actively closing the first switching device 31. This effectively prevents dangerous voltages from being present at unprotected contacts of the first connection group 21 of the shore connection 20 without a plug being inserted into the shore connection 20.

[0039] The advantage of this design is that a simple initial start-up is possible even when the on-board electrical system 40 is de-energized, for example because the first energy storage device 71 and the second energy storage device 72 are still empty. In this case, the first switching device 31 can be switched in a simple manner via the second connection group 22, thereby supplying the first sub-network 41 with voltage. After the essential components of the first sub-network 41 have been started up, for example also after the first energy storage device 71 has been at least partially charged, the second switching device 32 can be closed, thus connecting the first sub-network 41 to the second sub-network 42. The second energy storage device 72 can now also be charged. In this way, safe commissioning without manual intervention inside the unmanned underwater vehicle 10 is reliably possible.

[0040] Fig. 2 shows a modular unmanned underwater vehicle 10 consisting of a bow module, a stern module, and eight payload modules of various types arranged between them. The unmanned underwater vehicle 10 has an on-board electrical system 40 which extends as a ring through all modules and thus across the entire unmanned underwater vehicle. By way of example, the shore connection 20 is arranged in the bow module and designed analogously to the first example. The on-board electrical system 40 is routed through all modules, even modules that do not have any electrical functionality themselves. Modules with electrical functionality can, for example, have their own module electrical system 45, which is preferably detachably connected to the on-board electrical system 40 via a third switching device 33. If a significant malfunction occurs in the module electrical system 45, for example a short circuit, only the module electrical system 45 is disconnected from the on-board electrical system 40 by the third switching device 33.Thus, only the functionality of one module fails, while the rest remains fully functional. Modules can also have fourth switching devices 34 at the inputs of the on-board electrical system 40. If a malfunction occurs, for example, due to water ingress, the entire module is removed from the on-board electrical system 40. The on-board electrical system 40 is then no longer a ring connection, but even if one such module fails, all other modules can still be supplied with electrical energy via the on-board electrical system 40.

[0041] Reference symbol

[0042] 10 Unmanned underwater vehicle

[0043] 20 shore connection

[0044] 21 first connection group

[0045] 22 second connection group

[0046] 31 first switching device

[0047] 32 second switching device

[0048] 33 third switching device

[0049] 34 fourth switching device

[0050] 40 On-board network

[0051] 41 first subnetwork

[0052] 42 second subnetwork

[0053] 45 Modular electrical system

[0054] 51 first drive device

[0055] 52 second drive device

[0056] 61 first converter

[0057] 62 second first converter

[0058] 71 first energy storage units

[0059] 72 second energy storage units

[0060] 81 first second converter

[0061] 82 second second converter

[0062] 90 first fuel cell device first fourth converter hydrogen tank oxygen tank

Claims

Patent claims 1. Unmanned underwater vehicle (10) with an on-board electrical system (40) and a shore connection (20), wherein the on-board electrical system (40) is electrically connectable to the shore connection (20) via a first switching device (31), characterized in that the shore connection (20) has a first connection group (21) and a second connection group (22), wherein the first connection group (21) is designed for connection to the on-board electrical system (40), wherein the second connection group (22) is connected to the first switching device (31) for controlling the first switching device (31), wherein the first switching device (31) disconnects the connection between the on-board electrical system (40) and the first connection group (21) in the non-controlled state.

2. Unmanned underwater vehicle (10) according to claim 1, characterized in that the first connection group (21) and the second connection group (22) can only be contacted from the outside via a common connector.

3. Unmanned underwater vehicle (10) according to one of the preceding claims, characterized in that the shore connection (20) is arranged to be accessible from the outside.

4. Unmanned underwater vehicle (10) according to one of the preceding claims, characterized in that the on-board network (40) has a first sub-network (41) and a second sub-network (42), wherein the first sub-network (41) and the second sub-network (42) are electrically connectable via a second switching device (32), wherein the shore connection (20) is connectable to the first sub-network (41).

5. Unmanned underwater vehicle (10) according to claim 4, characterized in that the first switching device (31) is connected to the second switching device (32) via a connection control device.

6. Unmanned underwater vehicle (10) according to one of the preceding claims, characterized in that the first switching device (31) is connected to a central control device.

7. Unmanned underwater vehicle (10) according to one of the preceding claims, characterized in that the unmanned underwater vehicle (10) is a modular underwater vehicle, wherein the on-board network (40) is guided serially through the modules, wherein the on-board network (40) is designed as a closed ring.

8. Unmanned underwater vehicle (10) according to claim 7, characterized in that at least one module has a module electrical system (45), wherein the module electrical system (45) is electrically connectable to the on-board electrical system (40) via a third switching device (33).

9. Unmanned underwater vehicle (10) according to one of claims 7 to 8, characterized in that at least one module has at least one fourth switching device (34), wherein the fourth switching device (34) is arranged at the entry of the on-board network (40) into the module.

10. Unmanned underwater vehicle (10) according to one of the preceding claims, characterized in that the unmanned (10) underwater vehicle (10) has at least one first drive device (51), wherein the first drive device (51) is connected to the on-board network (40) via a first converter (61).

11. Unmanned underwater vehicle (10) according to claim 10, characterized in that the first converter (61) is designed to detect a short circuit in the power supply unit arranged behind the converter (61) by detecting a failure to achieve the required current flow.

12. Unmanned underwater vehicle (10) according to one of the preceding claims, characterized in that the unmanned underwater vehicle (10) has at least a first rudder, wherein the first rudder is connected to the on-board network (40) via a first second converter.

13. Unmanned underwater vehicle (10) according to one of the preceding claims, characterized in that the unmanned underwater vehicle (10) has at least one first energy storage device (71), wherein the first energy storage device (71) is connected to the on-board network (40) via a first third converter (81).

14. Unmanned underwater vehicle (10) according to one of the preceding claims, characterized in that the unmanned underwater vehicle (10) has at least a first fuel cell device (90), wherein the first fuel cell device (90) is connected to the on-board network (40) via a fourth converter (91).

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