Power supply for watercraft

Abstract

The invention relates to an electrical system (1) of a watercraft (2), comprising a DC network (3) with sub-networks (4) of different voltage levels, wherein an interface (5) is provided for connecting at least one mobile charging unit (6) to the electrical system (1), wherein the mobile charging unit (6) is designed as a battery (8) arranged in a torpedo shell (7). The invention also relates to a method for supplying power to watercraft (2).

Description

2024PF00441 1 Description TITLE Power supply for watercraft TECHNICAL AREA

[0001] The invention relates to an on-board electrical system of a watercraft and a method for supplying power to watercraft. BACKGROUND

[0002] Mobility faces the constant challenge of covering ever greater distances in ever shorter periods of time. Particularly in the field of electric mobility, a vehicle's range is critically examined in relation to its charging time. To significantly increase the range, the capacity of the storage medium, i.e., the battery, must be increased. However, without the use of new, technically improved battery technologies, this leads to a massive increase in volume and weight, which in turn increases energy consumption during operation. Therefore, a significant increase in capacity beyond a technical optimum is not possible.

[0003] In areas where charging infrastructure is lacking, such as at sea, energy consumption must be constantly monitored. Large and heavy range extenders, such as diesel generators including fuel tanks, are often installed to ensure the necessary energy supply. In the field of strategic maritime operations, new challenges arise, particularly with regard to new high-power consumers such as charging a swarm of unmanned underwater drones.

[0004] On submarines, and to some extent on surface ships and in electric cars, the primary energy source is a battery. The entire electrical system of these vehicles is a DC (direct current) network. Various subnetworks are generated and supplied from this network, for example, DC 220V, AC 115V, or DC 24V. The supply always proceeds from the higher to the lower voltage. 2024PF00441 2. In accordance with redundancy requirements, the networks are implemented multiple times to ensure a reliable energy supply.

[0005] The main batteries can be charged via generators or fuel cells. The maximum range of a vehicle or ship depends on the battery capacity, the amount of diesel or hydrogen in the tank, and the resulting energy consumption of the propulsion and onboard electrical systems. This means that the maximum range can be optimized by operating the propulsion engine ideally or by switching off electrical consumers. However, increasing the range by "externally absorbing" energy, similar to aerial refueling of fighter jets, is not possible.

[0006] These challenges and limitations highlight the need for innovative solutions to improve the range and efficiency of e-mobility applications, especially in areas without existing charging infrastructure. SUMMARY OF THE INVENTION

[0007] The object of the invention is to provide an onboard electrical system suitable for significantly increasing the range of watercraft without having to accept the disadvantages of increased volume and weight. Furthermore, the invention aims to provide a method for supplying power to watercraft.

[0008] The task directed towards an on-board network is solved by an on-board network of a watercraft, comprising a DC network with subnetworks of different voltage levels, wherein an interface for connecting at least one mobile charging unit to the on-board network is provided, wherein the mobile charging unit is designed as a battery arranged in a torpedo casing.

[0009] The use of a mobile charging unit in the form of a battery housed within a torpedo casing enables a flexible and mobile power supply. This mobile unit can be easily transported and connected at various points in the ship's electrical system to provide power. 2024PF00441 3. to provide or store power. Integrating the battery into a torpedo hull efficiently utilizes available space and can optimize the system's weight. This is particularly important in watercraft, where space and weight are often limited resources. The robust construction of a torpedo hull offers additional protection for the battery, increasing the reliability of the onboard electrical system. This is especially relevant in maritime environments, which can often be harsh and unpredictable. A DC power grid with multiple voltage levels can improve the energy efficiency of the onboard electrical system by minimizing conversion losses and optimizing power distribution. Finally, the modular nature of a mobile charging unit facilitates maintenance and replacement. If necessary, the unit can be easily removed and replaced with a new one, or even expanded, without requiring extensive work on the onboard electrical system.Additional mobile charging units can be added to meet energy needs or increase storage capacity.

[0010] In an advantageous embodiment of the invention, subnetworks are connected to the DC network via inverters or DC-DC converters, wherein the inverters or DC-DC converters are designed as bidirectional power converters.

[0011] Bidirectional power converters enable energy flow in both directions. This means that energy can flow not only from the DC grid to subnetworks, but also vice versa. This is particularly useful for integrating energy storage systems (such as batteries) that can feed energy back into the grid. Furthermore, bidirectional power converters enable flexible and efficient energy distribution. They can shift energy between different voltage levels and subnetworks as needed, increasing the overall efficiency of the system. By being able to transfer energy in both directions, bidirectional power converters can contribute to grid stabilization. They can absorb peak loads and store excess energy, thus increasing the reliability of the vehicle electrical system. Bidirectional power converters also facilitate the integration of energy storage devices such as batteries.These storage systems can absorb energy when it is abundant and release it when needed. This improves energy efficiency and security of supply. 2024PF00441 4

[0012] In a system with various energy sources (e.g., generators, batteries), bidirectional power converters can help optimize the use of these sources. They enable intelligent control and distribution of energy to minimize consumption and maximize efficiency. Furthermore, bidirectional power converters offer additional redundancy, as they can provide energy from other sources or subnetworks in the event of a failure of one energy source or part of the grid. This increases the reliability of the entire system.

[0013] It is advantageous if the mobile charging unit has a control wire or a fiber optic cable.

[0014] For example, once charging is complete, the mobile charging unit can be guided to an unmanned underwater vehicle to charge it from a safe distance. Fiber optic cables can transmit large amounts of data at high speeds, which is essential for real-time communication and control of the mobile charging unit. Fiber optic cables are also insensitive to electromagnetic interference, which is common in marine environments. This ensures reliable data transmission even in environments with high electromagnetic noise.

[0015] It is advantageous to connect mobile charging units in series or parallel. Connecting mobile charging units in series or parallel offers several benefits that improve the flexibility, efficiency, and reliability of the energy system.

[0016] Connecting charging units in series adds up the voltages of the individual units. This is useful when a higher voltage is required for specific applications or devices. At the same power output, a higher voltage results in a lower current. This can reduce losses in the wiring and increase system efficiency. Furthermore, lower currents allow the use of cables with a smaller cross-section, saving space and weight. 2024PF00441 5 On the other hand, the capacities of the individual mobile charging units add up when connected in parallel. Longer operating times are possible because the total energy storage capacity increases.

[0018] The problem of the invention, which is directed towards a method, is solved by connecting a mobile charging unit, which is designed as a battery arranged in a torpedo casing, to an on-board electrical system of the watercraft.

[0019] Connecting a mobile charging unit, designed as a battery housed within a torpedo casing, to a watercraft's electrical system offers significant advantages in terms of flexibility, space and weight savings, safety, energy efficiency, ease of maintenance, expandability, and reliability. These advantages contribute to maximizing the overall performance and operational efficiency of the watercraft.

[0020] It is advantageous if the mobile charging unit supplies the watercraft's electrical system with power, possibly by converting electricity from a lower to a higher voltage.

[0021] The ability to convert voltage allows the mobile charging unit to be flexibly deployed in different parts of the vessel's electrical system, which have varying voltage requirements. This flexibility is particularly useful in complex energy systems where different devices and systems require different voltages. By converting from lower to higher voltage, energy can be distributed more efficiently throughout the electrical system. Higher voltages result in lower currents, which reduces line losses. Lower currents also mean less energy is lost as heat, increasing the overall efficiency of the system. Efficient energy use and distribution can extend the vessel's operating time, as the stored energy is utilized optimally. More efficient energy distribution can also increase the vessel's range, since less energy is required for the same level of operation.

[0022] In an advantageous alternative embodiment of the invention, the mobile charging unit is connected to and charged by the watercraft. Subsequently 2024PF00441 6. The mobile charging unit is electrically disconnected from the vessel and guided via a control wire or fiber optic cable to another vessel to supply it with electrical power. Advantageously, this other vessel can be an unmanned underwater vehicle. A diesel generator, for example, can be used to charge the mobile charging unit via the vessel's electrical system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG 1 Exemplary network topology,

[0024] FIG 2 Parallel connection of recorded mobile charging units,

[0025] FIG 3 Series connection of recorded mobile charging units and

[0026] FIG 4 Power supply for a UUV. DESCRIPTION OF THE EXECUTION FORM EN

[0027] FIG 1 shows a well-known submarine power grid with a DC network 3 as the main power grid. Various subnetworks 4 are generated and supplied from this DC network 3, e.g., DC220V, AC115V, or DC24V.

[0028] The supply always proceeds from the higher to the lower voltage. Depending on redundancy requirements, the networks are implemented multiple times.

[0029] On the highest voltage level, in addition to the motors 17, the main batteries 18 and, via rectifiers 19, the diesel generators 15 are arranged. Other energy converters, such as fuel cells, are also possible. Inverters 9 or DC-DC converters 10 convert the DC voltage in the highest DC network 3 into the voltage required in the respective subnetwork 4. Unidirectional inverters 9 or DC-DC converters 10 are perfectly sufficient.

[0030] Charging the main batteries 18 is possible via generator 15 in the example shown in FIG. 1. The maximum range depends on the battery capacity and the number of batteries. 2024PF00441 7 liters of diesel or hydrogen and the resulting energy consumption of the driving and on-board network.

[0031] This means that the maximum range can be optimized by ideal operation of the drive motor 17 or by switching off on-board power consumers, but an increase by "external absorption" of energy, such as in the aerial refueling of fighter jets, is not possible.

[0032] FIG 2 shows the on-board network 1 of a watercraft 2, comprising a DC network 3 with subnetworks 4 of different voltage levels, wherein an interface 5 is provided for connecting at least one mobile charging unit 6 to the on-board network 1.

[0033] In the embodiment of FIG 2, subnetworks 4 are connected to the DC network 3 via inverters 9 or DC-DC converters 10, and the inverters 9 or DC-DC converters 10 are designed as bidirectional power converters.

[0034] Other networks can also be supplied via the bidirectional power converters 11. According to FIG. 2, a mobile charging unit 6 with a fully charged battery system for DC 220V could supply the DC network 3 (i.e., the vehicle network voltage) via the DC-DC converter 10, and also the AC 115V via an inverter 9. A redundant direct connection, DC 200V<-> AC 115V, depends on space and weight requirements. The invention is not limited to a single mobile charging unit 6. In the embodiment shown in FIG. 2, four mobile charging units 6 are connected in parallel and supply parts of the onboard electrical system 1, e.g., for life support measures in the DC 220V network in the event of a submarine accident. [0C35] Another option is to connect several mobile charging units 6 in series, which directly supply the DC network 3. This is shown in FIG 3, where, by way of example, four mobile charging units 6 for DC220V are connected in series. According to the invention, the mobile charging unit 6 is designed as a battery 8 arranged in a torpedo casing 7, as shown in FIG. 4. The mobile charging unit 6 is like a known torpedo, but without an explosive charge, and features 2024PF00441 8 has its own drive and a control wire 12 or a fiber optic cable 13. Via this fiber optic cable 13, for example, the mobile charging unit 6 loaded in the submarine 16 can be controlled to a remote further watercraft 14, for example a UUV (stands for "Unmanned Underwater Vehicle", i.e. an unmanned underwater vehicle), so that charging of the further watercraft 14 can be carried out at a safe distance from the submarine 16. REFERENCE NUMBER ENLIST 1 Onboard electrical system (= electrical system for a watercraft) 2 Watercraft 3 DC network 4 subnetwork 5 Interface 6 mobile charging units 7 Torpedo casing 8 batteries 9 inverters 10 DC / DC converters 11 (bidirectional) power converters 12 Control wire 13 optical fibers 14 other watercraft 15 Diesel generator 16 submarines 17 Engine 18 Main battery 19 rectifiers

Claims

2024PF00441 9 Claims What is claimed:

1. An on-board electrical system (1) of a watercraft (2), comprising a DC network (3) with subnetworks (4) of different voltage levels, wherein an interface (5) for connecting at least one mobile charging unit (6) to the on-board electrical system (1) is provided, characterized in that the mobile charging unit (6) is designed as a battery (8) arranged in a torpedo casing (7).

2. The on-board network (1) according to claim 1, wherein subnetworks (4) are connected to the DC network (3) via inverters (9) or DC-DC converters (10) and wherein the inverters (9) or DC-DC converters (10) are designed as bidirectional power converters (11).

3. The on-board network (1) according to one of the preceding claims, wherein the mobile charging unit (5) has a control wire (12) or a light guide (13).

4. The vehicle electrical system (1) according to one of the preceding claims, wherein mobile charging units (6) are connected in series or in parallel.

5. Method for supplying power to watercraft (2), wherein a mobile charging unit (6), which is designed as a battery (8) arranged in a torpedo casing (7), is connected to an on-board power supply (1) of the watercraft (2).

6. Method according to claim 5, wherein the mobile charging unit (6) supplies the on-board network (1 ) of the watercraft (2) with electrical energy, optionally also converting current from a lower to a higher voltage.

7. Method according to claim 5, wherein the mobile charging unit (6) is connected to and charged by the on-board network (1) and the mobile charging unit (6) is electrically disconnected from the watercraft (2) and guided via a control wire (12) or a fiber optic cable (13) to another watercraft (14) to supply it with electrical energy. 2024PF00441 10 8. Method according to claim 7, wherein an unmanned underwater vehicle (14) is loaded as a further watercraft (14).

9. Method according to one of claims 7 or 8, wherein the mobile charging unit (6) is charged via the vehicle electrical system (1) with a diesel generator (15).

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